//#include<bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<vector>
#include<cmath>
#include<numeric> // __GCD()
#include<stack>
#include<string.h>
#include<math.h>
#include<set>

using namespace std;

#define ll long long
#define all(v) v.begin(),v.end()

int main(){

    ll r;
    double x,y; cin>>r>>x>>y;

    double a=sqrt(x*x+y*y);

    ll b=a;
    if(a-b==0){
        if(b%r==0){
            cout<<b/r<<endl;
        }
        else{
            if(b<r) cout<<2<<endl;
            else cout<<b/r+1<<endl;
        }
    }
    else{
        if(b<r) cout<<2<<endl;
        else cout<<b/r+1<<endl;
    }

    return 0;
}
#include <bits/stdc++.h>

int main() {
    int a, b;
    std::cin >> a >> b;
    for (int i = b - a; i > 0; i--) {
        int l = a / i * i; if (l < a) l += i;
        int r = b / i * i; if (r + i <= b) r += i;
        if (l < r) {
            std::cout << i << '\n';
            break;
        }
    }
}