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