#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

int main(){

    ll A, B, C, D;
    bool f=0;
    cin >> A >> B >> C;
    for (int i=1; i<=2e5; i++){
        D = A*i;
        if (D-B>0) D -= B;
        if (D == C){
            f = 1;
            cout << i << endl;
        }
    }

    if (!f) cout << -1 << endl;

    return 0;
}