#include <bits/stdc++.h>
using namespace std;

int main()
{
	int m, t, s;
	cin >> m >> t >> s;

	if(t)
	{ 
		int k = s / t + (s % t != 0);
		cout << max(0, m - k) << endl;
	} 
	else 
		cout << 0 << endl; 

	return 0;
}