#include <iostream>
using namespace std;

// 快速幂取模函数，计算 (base^exponent) % mod
int fastPower(int base, int exponent, int mod) {
    int result = 1;
    base %= mod;
    while (exponent > 0) {
        if (exponent & 1) {
            result = (result * base) % mod;
        }
        base = (base * base) % mod;
        exponent >>= 1;
    }
    return result;
}

int main() {
    int p, b, n;
    cin >> p >> b >> n;
    for (int l = 0; l < p; l++) {
        if (fastPower(b, l, p) == n) {
            cout << l << endl;
            return 0;
        }
    }
    cout << -1 << endl;
    return 0;
}

#include <iostream>
using namespace std;

// 计算最大公约数，用于判断两个数是否互质
long long gcd(long long a, long long b) {
    return b == 0? a : gcd(b, a % b);
}

// 快速幂取模函数，用于高效计算 (a^n) % m
long long powMod(long long a, long long n, long long m) {
    long long res = 1;
    a %= m;
    while (n > 0) {
        if (n & 1) {
            // 如果n的二进制最低位为1，累乘当前的a
            res = res * a % m;
        }
        a = a * a % m;
        n >>= 1;  // 右移一位，相当于n /= 2
    }
    return res;
}

int main() {
    long long p, b, n;
    cin >> p >> b >> n;
    // 判断b与p是否互质，如果不互质直接输出 -1
    if (gcd(b, p)!= 1) {
        cout << -1 << endl;
        return 0;
    }

    bool found = false;
    for (long long l = 1; l < p; l++) {
        if (powMod(b, l, p) == n) {
            cout << l << endl;
            found = true;
            break;
        }
    }
    if (!found) {
        cout << -1 << endl;
    }
    return 0;
}