#include <bits/stdc++.h>
using namespace std;
#define int long long
// 龟速乘
int gui(int a, int b, int p) {
    int res = 0;
    while (b) {
        if (b & 1) res = (res + a) % p;
        a = (a + a) % p;
        b >>= 1;
    }
    return res;
}

int main() {
    int a, b, p;
    cin >> a >> b >> p;
    printf("%lld\n", gui(a, b, p));
    return 0;
}