#include<bits/stdc++.h>
using namespace std;
int m,t,s;
int main(){
	cin>>m>>t>>s;
	if(s%t==0){
		cout<<max(m-s/t,0)<<endl;
	}
	else 
	    cout<<max(m-s/t-1,0)<<endl;
	return 0;
}