#include <stdio.h>
typedef long long LL;
inline LL mult_mod(LL a, LL b, LL m){ // a * b % m
    a = (a % m + m) % m;
    b = (b % m + m) % m;
    LL ans = a * b - (LL)((long double) a * b / m + 0.5) * m;
    return ans < 0? ans + m : ans;
}

int main(){
    LL x, y, m;
    scanf("%lld%lld%lld", &x, &y, &m);
    printf("%lld\n", mult_mod(x, y, m));
    return 0;
}