单点时限: 2.0 sec
内存限制: 256 MB
Write a program to calculate integer square roots.
Its only line consists of an integer 0⩽n≤263 .
Its only line consists of the smallest nonnegative integer q such that q2⩾n .
122333444455555
11060446
1223334444555550.5≈11060445.038765619