I have got AC for this problem but my solution is quite inefficient

http://acm.timus.ru/status.aspx?space=1&num=1119&author=82952

It takes me 0.156 seconds to compute the answer, but there are many ppl who got solution in 0.015 secs.If possible please email me one of the efficient solution (C++ one).my email address is pjas002@aucklanduni.ac.nz

Thanks