#include <bits/stdc++.h>
#include <iostream>
#include <iomanip>
#include <cmath>
#include <math.h>
#include <algorithm>
#include <cstring>
using namespace std;
const int N = 1e5 + 10;
const int INF = 0x3f3f3f3f;
int main()
{
	int n , x , y , c;
	cin >> n >> x >> y;
	c = y / x;
	if( y % x > 0 )
	{
		if( n - c < 0 )
		{
			cout << 0 << endl;
		}
		else
		{
			c = c + 1;
			c = n - c;
			cout << c << endl;
		}
	}
	else
	{
		if( n - c < 0 )
		{
			cout << 0 << endl;
		}
		else
		{
			c = n - c;
			cout << c << endl;
		}
	}
    return 0;
}