#include<iostream>
#include<vector>
#include<cmath>

using namespace std;

int main()
{
      #ifndef ONLINE_JUDGE
            freopen("input.txt", "rt", stdin);
            freopen("output.txt", "wt", stdout);
            #endif

    int n,m,y;
    long double x;
    long double time;
    vector< long double >vec;

    cin >> n >> m >> y;
    if( n <= 0 || n >= 999)
        exit(1);
    if( m <= 1 || m >= 999)
        exit(1);
    if( y <= 0 || y >= 99)
        exit(1);

    for( x = 0; x < m; x++)
    {
        time = pow(x, n);
        if( (unsigned long)time % m == y)
            vec.push_back(x);
    }
    if( vec.size() == 0)
        cout << "-1";

    else
    {
    for( unsigned int i = 0; i < vec.size(); i++)
    {
        cout << vec[i] << " ";
    }
    }

    return 0;
}

Don't use pow~
Actually, the result of pow can exceed your data type(long).

tips.
(A*A) mod m = (A mod m) * (A mod m)

Edited by author 01.10.2009 11:32

(A * A) mod m = ((A mod m) * (A mod m)) mod m