#include<bits/stdc++.h>
int main(){
	int M=0,J=0;
    for (int i = 1; i <= 12; i++){
        int Y;
        std::cin>>Y;
        J+=300-Y;
        if(J<0){
            std::cout<<-i;
            return 0;
        }
        M=J/100;
        J%=100;
    }
    std::cout << M*120+J;
    return 0;
}