看代码

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

}
return 0;

}