In the problem 492B(https://codeforces.com/contest/492/problem/B) can someone point out where I am doing mistake, in the third testcase Jury's answer is 22258199.5000000000 but my code is giving output 2.22582e+07 I am not getting where I have done wrong I would be highly obliged if someone help me....

my solution-https://codeforces.com/contest/492/submission/157284959