#include<iostream>
using namespace std;
int main()
{
int n,h,m;
std::cin >> n >> h >> m;
if(m%h==0)
std::cout << n - m / h << endl;
else
std::cout << n - m / h - 1 << endl;
return 0;
}
#include<iostream>
using namespace std;
int main()
{
int n,h,m;
std::cin >> n >> h >> m;
if(m%h==0)
std::cout << n - m / h << endl;
else
std::cout << n - m / h - 1 << endl;
return 0;
}