#include <bits/stdc++.h>
using namespace std;

int main(){
    double a,b,c,r;
    cin>>a>>b>>c;
    r = a + b + c;
    if(r >= 200){
    	r = r * 0.8;
	}else{
		r = r * 0.9;
	}
    cout<<fixed<<setprecision(1)<<r;
}