#include<stdio.h>
int main()
{
    int i,j=0,k,t=0;
    for(i=1;i<=12;i++)
    {
        t=t+300;
        scanf("%d",&k);
        if(k>t)
        {
            printf("%d",-i);
            return 0;
            }
            else
            while(k<=t-100)
            {
                t=t-100;
                j=j+100;
                }
                t=t-k;
                }
            j=j*1.2+t+1;
    printf("%d",j);
    return 0;
    }