#include <cstdio>
using namespace std;
int main()
{
    int B, A, S;
    while (scanf("%d%d%d", &B, &A, &S) != EOF){
        int carry = 0, len = 0, x = A;
        while (1){
            int tmp = x * S + carry;
            carry = tmp / B;
            x = tmp % B;
            len++;
            if (carry == 0 && x == A) break;
        }
        printf("%d\n", len);
    }
    return 0;
}