#include<iostream>
#include<cmath>

using namespace std;

int main()
{
	int st = 0, end = 0;
	double per = 0.0, pro = 0.0;
	cin >> st >> per >> pro;
	int num = pro / per;
	double num_0 = pro / per - num;
	if (num_0 >= st)
		end = 0;
	else
		if (num_0 != 0)
		{
			num = num + 1;
		}
		else
		{
			num = num;
		}
		end = st - num;
	cout << end;
	return 0;
}```