cf 1517A

#include<stdio.h>

int sum(long long n)
{
    int s = 0;
    while(1)
    {
        s += n % 10;
        n /= 10;
        if(n == 0) break;
    }
    return s;
}

int main()
{
    int t;
    scanf("%d", &t);
    while(t--)
    {
        long long n;
        int ans;
        scanf("%lld", &n);
        if(n % 2050 != 0) printf("-1\n");
        else
        {
            n /= 2050;
            ans = sum(n);
            printf("%d\n", ans);
        }
    }
}