#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;
int main()
{
    int n,m,t,s;
    cin>>n>>m>>t;
    if(m==0||s*t>=m)
        cout<<0;
    else
    {   
        s=ceil((t*1.0)/(m*1.0));
        cout<<n-s;
    }
    return 0;
}