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