kc2班yyy小恐龙600分谁敢挑战

a,b,c,d =map(float, input().split()) 
e =1/(1/a+1/b) 
f =1/(1/a+1/b+1/c+1/d) 
print(f"{e:.2f}") 
print(f"{f:.2f}")

#include <bits/stdc++.h> using namespace std; double a,b,c,d,e,f; int main() { cin>>a>>b>>c>>d; e=1/(1/a+1/b); f=1/(1/a+1/b+1/c+1/d); printf("%.2f",e); cout<<endl; printf("%.2f",f); return 0; }

#include <iostream>
using namespace std;

int main()
{
    double a,b,c,d,s;
    cin>>a>>b>>c>>d;
    printf("%.2f",1/((1/a)+(1/b)));cout<<endl;
    s=1/((1/a)+(1/b)+(1/c)+(1/d));
    printf("%.2f",s);
    return 0;
}

#include <bits/stdc++.h>

A, B, C, D = map(float, input().split()) ab_time = 1 / (1 / A + 1 / B) abcd_time = 1 / (1 / A + 1 / B + 1 / C + 1 / D) print(f"{ab_time:.2f}") print(f"{abcd_time:.2f}")