#include <iostream>
using namespace std;

int main() {
    int m, t, s;
    cin >> m >> t >> s;
    
    if (t == 0) {
        // If eating takes 0 minutes, she eats all apples immediately
        cout << 0 << endl;
        return 0;
    }
    
    int eaten = s / t;
    if (s % t != 0) {
        eaten++; // she's in the process of eating the next apple
    }
    
    int remaining = m - eaten;
    if (remaining < 0) {
        remaining = 0; // she can't have negative apples left
    }
    
    cout << remaining << endl;
    return 0;
}