#include <bits/stdc++.h>
using namespace std;
int main() {
	float a,b,c,h,p;
	cin>>a>>b>>c;
	h=a+b+c;
	if(h>=200){
	p=h*0.8;
	}else{
	p=h*0.9;
	}
	printf("%.1f",p);
    return 0;
}
/**************************************************************
	Problem: 1624
	User: fuhoubin
	Language: C++
	Result: Accepted
	Time:13 ms
	Memory:2072 kb
****************************************************************/