简单

#include<bits/stdc++.h>
using namespace std;
int main(){
    ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
    double n,x,y;
    cin>>n>>x>>y;
    if(n-y/x<1) cout<<0;
    else cout<<floor(n-(y/x));
    return 0;
}