Step 0 Step 1 Step 2 Step 3 Step 4 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | | | | | + + +---+ + + +---+ + + +---+ + + +---+ + + +---+ | | | | | | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ |XXX| |XXX| | | |XXX| | | |XXX| | | |XXX| | | |XXX| +---+---+---+---+ + +---+---+---+ + +---+---+---+ + +---+---+---+ + +---+---+---+ | | | | | | | | | | | | | | | | | | |XXX| + +---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | |XXX| | | | |XXX| | | | |XXX| | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 5 Step 6 Step 7 Step 8 Step 9 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | |XXX| | |XXX| | |XXX| | | | | | | + + +---+ + + +---+ + +---+ + +---+ + + + + + + | | |XXX| | | |XXX| | |XXX| | |XXX| | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | |XXX| | | | | | | | | | | | | |XXX| | | + +---+---+---+ + +---+---+---+ + +---+---+---+ + +---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | |XXX| | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 10 Step 11 Step 12 Step 13 Step 14 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | | | | | + + + + + + + + + + + + + + + + + + + + | | | | | | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | |XXX| | | |XXX| | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ |XXX| | | | |XXX| | | |XXX| | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | |XXX| | | |XXX|XXX| |XXX|XXX| | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 15 Step 16 Step 17 Step 18 Step 19 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | |XXX| | | + + + + + + + + + + + + + + + + +---+ + + | | | | | | | | | | | | | | | | |XXX| | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | |XXX| | |XXX| | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ + +---+---+---+ |XXX|XXX| | | |XXX| |XXX| | |XXX| | | | |XXX| | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 20 Step 21 Step 22 Step 23 Step 24 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | |XXX| | | | |XXX| | | | | | | | | | | | | + +---+ + + + +---+ + + +---+ + + +---+ + + +---+ | |XXX| | | | |XXX| | | |XXX| | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | |XXX| | | |XXX| | |XXX| | + +---+---+---+ + +---+---+---+ + +---+---+---+ + +---+---+---+ + +---+---+---+ | | | | | | | | | | | | | | | | | | |XXX| | | | |XXX| +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 25 Step 26 Step 27 Step 28 Step 29 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | |XXX| | | | |XXX| | + + +---+ + + +---+ + + +---+ +---+ +---+ + +---+---+ | | | | | | | | | | | | |XXX| | | | |XXX| | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | |XXX| | | |XXX| | |XXX| | | | | | | | | | | + +---+---+---+ + +---+---+---+ +---+ +---+---+ + + +---+---+ + + +---+---+ | | |XXX| | | |XXX| | | |XXX| | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 30 Step 31 Step 32 Step 33 Step 34 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | | | | | + +---+---+ + +---+---+ + +---+---+ + +---+---+ + +---+---+ | |XXX|XXX| | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | |XXX|XXX| | | | |XXX| | | | | | | | | | | + + +---+---+ + + +---+---+ + + +---+---+ + + +---+---+ + + +---+---+ | | | | | | | | | | | | |XXX| | | | |XXX|XXX| | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | |XXX|XXX| +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 35 Step 36 Step 37 Step 38 Step 39 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | |XXX|XXX| | | | |XXX|XXX| | + +---+---+ + +---+---+ + +---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ + +---+---+ + +---+---+ | | | | | |XXX| | | | |XXX|XXX| | | | | | | | | | | + + +---+---+ +---+ +---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | | | | | +---+---+---+---+ + +---+---+---+ + + +---+---+ + + +---+---+ + + +---+---+ |XXX|XXX| | | |XXX| | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 40 Step 41 Step 42 Step 43 Step 44 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | |XXX|XXX| | | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | |XXX|XXX| | |XXX| | |XXX| | | | | | | + +---+---+ + +---+---+ + +---+---+ +---+ +---+ + + +---+ | | | | | | | | | |XXX| | |XXX| | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | |XXX| | | + + +---+---+ + + +---+---+ + + +---+---+ + + +---+---+ +---+ +---+---+ | | | | | | | | | | | | | | | | |XXX| | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 45 Step 46 Step 47 Step 48 Step 49 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | | | |XXX| + + +---+ + + +---+ + + +---+ + + +---+ + + +---+ | | | | | | | | | | | | | | |XXX| | | |XXX| +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | |XXX| | | | |XXX| | | |XXX| | | |XXX| | | | | + +---+---+---+ + +---+---+---+ + +---+---+---+ + +---+---+---+ + +---+---+---+ | |XXX| | | |XXX| | | | |XXX| | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 50 Step 51 Step 52 Step 53 Step 54 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | |XXX| | |XXX| | | | | | | | | | | | | | | + +---+ + +---+ + + + + + + + + + + + + + + | |XXX| | |XXX| | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | |XXX| | | | |XXX| | | |XXX| | + +---+---+---+ + +---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | |XXX| | | |XXX| | | | |XXX| | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 55 Step 56 Step 57 Step 58 Step 59 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | |XXX|XXX| | |XXX|XXX| | |XXX|XXX| | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | |XXX|XXX| | | | | | | | | | | | | + + + + + + +---+---+ + + +---+---+ + + +---+---+ + + +---+---+ | | | | | | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+ + +---+---+ + +---+---+ + +---+---+ + | |XXX|XXX| | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 60 Step 61 Step 62 Step 63 Step 64 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | |XXX| | | | | | | | | | | | | | | | | | | | | | | + +---+---+---+ + + +---+---+ + + +---+---+ + + +---+---+ + + +---+---+ | | | | | | | | | | | | | | | | | | | | +---+ +---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ |XXX| | | |XXX|XXX| | | | | | | | | | | +---+---+ + +---+---+ + +---+---+ + +---+---+ + +---+---+ + | | | | | | |XXX|XXX| | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | |XXX|XXX| | | | |XXX|XXX| | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 65 Step 66 Step 67 Step 68 Step 69 +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | | | | | | | | | | | | | | | | | + + +---+---+ + + +---+---+ + + +---+---+ + + +---+---+ + + +---+---+ | | | | | | | | | | | | | | | | | | | | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | |XXX|XXX| |XXX|XXX| | | | | | | | +---+---+ + +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ | | | | | | | | | |XXX|XXX| | | |XXX| | +---+---+---+---+ +---+---+ + +---+---+ + +---+---+ + +---+---+ + | | |XXX|XXX| | | | | | | | | | | | | | |XXX| | +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ +---+---+---+---+ Step 70 +---+---+---+---+ | | | | | + + +---+---+ | | | | +---+---+---+---+ | | | +---+---+---+---+ | | |XXX| +---+ +---+ | | |XXX| +---+---+---+---+