Standard input is empty

18446744073709551616
Step 1 foo = 2
Step 2 foo = 4
Step 3 foo = 8
Step 4 foo = 16
Step 5 foo = 32
Step 6 foo = 64
Step 7 foo = 128
Step 8 foo = 256
Step 9 foo = 512
Step 10 foo = 1024
Step 11 foo = 2048
Step 12 foo = 4096
Step 13 foo = 8192
Step 14 foo = 16384
Step 15 foo = 32768
Step 16 foo = 65536
Step 17 foo = 131072
Step 18 foo = 262144
Step 19 foo = 524288
Step 20 foo = 1048576
Step 21 foo = 2097152
Step 22 foo = 4194304
Step 23 foo = 8388608
Step 24 foo = 16777216
Step 25 foo = 33554432
Step 26 foo = 67108864
Step 27 foo = 134217728
Step 28 foo = 268435456
Step 29 foo = 536870912
Step 30 foo = 1073741824
Step 31 foo = 2147483648
Step 32 foo = 4294967296
Step 33 foo = 8589934592
Step 34 foo = 17179869184
Step 35 foo = 34359738368
Step 36 foo = 68719476736
Step 37 foo = 137438953472
Step 38 foo = 274877906944
Step 39 foo = 549755813888
Step 40 foo = 1099511627776
Step 41 foo = 2199023255552
Step 42 foo = 4398046511104
Step 43 foo = 8796093022208
Step 44 foo = 17592186044416
Step 45 foo = 35184372088832
Step 46 foo = 70368744177664
Step 47 foo = 140737488355328
Step 48 foo = 281474976710656
Step 49 foo = 562949953421312
Step 50 foo = 1125899906842624
Step 51 foo = 2251799813685248
Step 52 foo = 4503599627370496
Step 53 foo = 9007199254740992
Step 54 foo = 18014398509481984
Step 55 foo = 36028797018963968
Step 56 foo = 72057594037927936
Step 57 foo = 144115188075855872
Step 58 foo = 288230376151711744
Step 59 foo = 576460752303423488
Step 60 foo = 1152921504606846976
Step 61 foo = 2305843009213693952
Step 62 foo = 4611686018427387904
Step 63 foo = 9223372036854775808
Step 64 foo = 18446744073709551616
18446744073709551616