#include<bits/stdc++.h> using namespace std; int main(){ int a,b,c; cin>>a>>b>>c; if(b==0)cout<<a; else{ int d=c%b; if(d!=0){ c-=d; c/=b; c++; a-=c; cout<<a; }else{ c/=b; a-=c; cout<<a; } } return 0; }