#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
int main()
{
	int n,x,y,ans;
	scanf ("%d %d %d",&n,&x,&y);
	ans=n-y/x;
	if (y%x!=0) {
		ans-=1;
	}
	printf ("%d",ans);
	return 0;
}