#include<bits/stdc++.h> using namespace std; int main() { double r1,r2; cin>>r1>>r2; printf("%.2f",1.0/(1.0/r1+1.0/r2)); return 0; }
By signing up a 追梦算法网 universal account, you can submit code and join discussions in all online judging services provided by us.
Using your 追梦算法网 universal account