#include <cstdio>
int save,cur,touse;
int main()
{
    for(int i=1; i<=12; i++)
    {
        cur+=300;
        scanf("%d",&touse);
        if(touse>cur)
        {
            printf("-%d",i);
            return 0;
        }
        cur-=touse;
        save+=cur/100*100;
        cur%=100;
    }
    printf("%d",cur+save*6/5);
    return 0;
}