#include<bits/stdc++.h>
using namespace std;
int main(){
    int h[12],q[12]={300,300,300,300,300,300,300,300,300,300,300,300},l=0;
    for(int i=0;i<12;i++) cin>>h[i];
    for(int i=0;i<12;i++){
         if(h[i]>q[i]) {
             cout<<(i+1)*-1;
             return 0;
         }
        q[i]-=h[i];
        l+=q[i]/100*100;
        if(i!=11) q[i+1]+=q[i]%100;
    }
    q[11]-=q[11]/100*100;
    l+=l/5;
    q[11]+=l;
    cout<<q[11];
}