#include<iostream>
#include<cstdio>
#include<cmath>
using namespace std;
int main()
{
 int m,t,s,left;
 cin>>m>>t>>s;
 left=m;
 
 if(t==0)
 {
     cout<<0;
     return 0;
  }
 left=m-ceil(double(s/t));
    if(left<=0)
    {
        printf("0");
    }
    else printf("%d",left);
        return 0;
    }