程序代码：

#include <cstdio>

long long PowerMod(long long a, int b, int k)
{
    long long tmp = a, ret = 1;
    while (b)
    {
        if (b & 1)
            ret = ret * tmp % k;
        tmp = tmp * tmp % k;
        b >>= 1;
    }
    return ret ;
}

int main()
{
    long long a = 2;
    int b,  k = 9973;
    while(1)
    {
        scanf("%d",&b);
        if ( b == 0)
            break;
        else if ( b < 0)
            continue;
        printf("%d\n",PowerMod(a, b, k) -1);
    }

    return 0;
}