#include <cstdio>

using namespace std;

int GCD (int A, int B, int &X, int &Y)
{
    if (B==0)
    {
        X=1;
        Y=0;
        return A;
    }
    int X0, Y0, D;
    D=GCD (B, A%B, X0, Y0);
    X=Y0;
    Y=X0-(A/B)*Y0;
    return D;
}

int main()
{
    freopen ("oak.in", "r", stdin);
    freopen ("oak.out", "w", stdout);
    int T;
    scanf ("%d", &T);
    for (; T>0; --T)
    {
        int A, B, C;
        scanf ("%d %d %d", &A, &B, &C);
        int D, X, Y;
        D=GCD (A, B, X, Y);
        if (C%D)
        {
            printf ("-1\n");
        }
        else
        {
            printf ("%d\n", X*(C/D)+Y*(C/D));
        }
    }
    return 0;
}