知识点：运算 

#include <iostream>
using namespace std;

int main() {
    int n = 0;
    int h = 0;
    int m = 0;
    int res = 0;

    cin >> n >> h >> m;

    m = (m % h == 0) ? m : m + h;
    res = n - m / h ;

    cout << res;

    return 0;
}