#include<iostream>
#include<stdio.h>
using namespace std;
int main() {
	int i,month,left=0,save=0,sum,plan,flag=0;
	for(month=1; month<=12; month++) {
		left+=300;
		scanf("%d",&plan);
		left = left - plan;
		if(left<0) {
			flag=1;
			break;
		} else {
			i = left/100;
			save += (100*i);
			left -= (100*i);
		}
	}
	if(flag>0)
		printf("-%d",month);
	else {
		sum=((1.2*save) + left);
		printf("%d",sum);
	}
	return 0;
}