#include<iostream>
using namespace std;
int main(){
	int m,t,s;
	cin>>m>>t>>s;
	if(t==0){
		cout<<m<<endl;
	}else if(m*t<s){
		cout<<m<<endl;
    }else{
    	cout<<(m*t-s)/t<<endl;
	}
	return 0;
}