#include<bits/stdc++.h>
using namespace std;
int main() {
	int a,b,s;
	cin>>a>>b>>s;
	if(b==0)cout<<0;
	if(a-ceil(s/b)<=0){
		cout<<0;
	}else{
		cout<<a-ceil(s/b);
	}
	return 0;
}