//程序名:新的C++程序
//作者: 


#include<bits/stdc++.h>
using namespace std;
int m,t,s,c=0;
int main(){
cin>>m>>t>>s;
if(t==0)
{cout<<m;return 0;}
c=s/t;
if(s%t!=0)
{
cout<<max(0,m-c-1)<<endl;return 0;
}
cout<<max(0,m-c)<<endl;return 0;
}