#include<iostream> using namespace std; int main(){ int y,n,x; cin>>y>>n>>x; if(n%x==0) { if(y<x/n) { cout<<"0"; } else { cout<<y-n/x; } } if(n%x!=0) { if(y<x/n) { cout<<"0"; } else { cout<<y-n/x-1; } } }