Please take a look at: 4021643 and 6576225. They are exactly same but one runs in 2s the other in 0.1s, Later solution sent 10 months after earliar one. My own submission got TLE 130759328 while in my computer, runs in just 0.188s
$time ./block_towers
real 0m0.188s
user 0m0.132s
sys 0m0.036s
Whats going on? I think that would be a good idea to improve FPC version from 3.0.4 to 3.2.0;
Thanks (^_^)/