borisko with -O3
        0.27 real         0.10 user         0.09 sys
        0.27 real         0.07 user         0.13 sys
        0.26 real         0.12 user         0.09 sys
        0.29 real         0.10 user         0.09 sys
        0.27 real         0.12 user         0.09 sys
puzzle with -O3
        0.75 real         0.16 user         0.11 sys
        0.81 real         0.17 user         0.13 sys
        0.46 real         0.15 user         0.13 sys
        0.35 real         0.19 user         0.06 sys
        0.36 real         0.17 user         0.08 sys
borisko
        1.28 real         0.74 user         0.10 sys
        1.08 real         0.73 user         0.09 sys
        1.29 real         0.71 user         0.11 sys
        1.03 real         0.74 user         0.08 sys
        1.09 real         0.71 user         0.13 sys
puzzle
        1.13 real         0.72 user         0.12 sys
        1.17 real         0.71 user         0.11 sys
        1.10 real         0.70 user         0.14 sys
        1.14 real         0.70 user         0.12 sys
        1.29 real         0.74 user         0.08 sys