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