#include<bits/stdc++.h>
using namespace std;
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')';}
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) {os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
void dbg_out() { cerr << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cerr << ' ' << H; dbg_out(T...); }
template<typename T> void dbg_a(T *a,int l,int r){cerr<<" {";for(int i = l;i<r;i++) cerr<<a[i]<<", ";cerr<<a[r]<<"}"<<endl;}
typedef long long ll;
#define int ll
inline int read(){
    int f(1),r(0);char c(getchar());
    while(c<'0'||c>'9'){if(c == '-') f = -1; c = getchar();}
    while(c>='0'&&c<='9'){ r = (r<<1) + (r<<3) + c - '0';c = getchar();}
    return f*r;
}
typedef pair<int,int> PII;
#define fi first
#define se second
#define mst(a,b) memset(a,b,sizeof(a))
#define For(i,a,b) for(int i = a;i<=b;i++)
#define For_(i,a,b) for(int i = a;i>=b;i--)
#define _for(i,a) for(int i = 0;i<a;i++)
#define _sum(a,l,r) accumulate(a + l,a + r + 1,0)
#define All(x) x.begin(),x.end()
#define lowbit(x) ((-x)&x)
//    For(i,1,n) For(j,1,m) printf("f[%lld][%lld] = %lld\n",i,j,f[i][j]);
//const ll INF = 0x3f3f3f3f3f3f3f3f;
const int INF = 0x3f3f3f3f;
const int N = 1000 + 6,M = 2e5*2 + 6,Q = 2e6 + 5;
const int mod = 2017;
int n,m;

void solve(){
    int R = read();
    int X = read(),Y = read();
    //dbg_out((X*X + Y*Y)/R*R);
    int ans = ceil(sqrt((long double)(X*X + Y*Y)/(long double)(R*R)));
    if(R*R > X*X + Y*Y){
        ans = 2;
    }
    cout<<ans<<"\n";
}
signed main(){
    int T = 1;
    //T = read();
    while(T--) solve();
    system("pause");
    return 0;
}
#include <algorithm>
#include <iostream>
#include <math.h>
#include <stdio.h>
#include <string>
#include <sstream>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <cmath>
#include <iterator>
#include <queue>
#define ll long long int
using namespace std;

bool isOk(ll r,ll x,ll y,ll num){
	if( (x*x + y*y) <= (num*num*r*r)){
		return true;
	}else{
		return false;
	}
}

int main()
{
	ll R,X,Y;
	cin>>R>>X>>Y;
	if( R*R > X*X + Y*Y){
		cout<<2<<endl;
	}else{
		for(ll i = 0; i < 2000000; i++){
			if( X*X + Y*Y <= i*i*R*R){
				cout<<i<<endl;
				break;
			}
		}
	}
	return 0;
}

