#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <climits>
#include <cstring>
#include <cassert>


using namespace std;
//using namespace atcoder;

#define REP(i, n) for (int i=0; i<(n); ++i)
#define RREP(i, n) for (int i=(int)(n)-1; i>=0; --i)
#define FOR(i, a, n) for (int i=(a); i<(n); ++i)
#define RFOR(i, a, n) for (int i=(int)(n)-1; i>=(a); --i)

#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()

#define DUMP(x) cerr<<#x<<" = "<<(x)<<endl
#define DEBUG(x) cerr<<#x<<" = "<<(x)<<" (L"<<__LINE__<<")"<<endl;

template<class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
    os << "[";
    REP(i, SZ(v)) {
        if (i) os << ", ";
        os << v[i];
    }
    return os << "]";
}

template<class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
    return os << "(" << p.first << " " << p.second << ")";
}

template<class T>
bool chmax(T &a, const T &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
bool chmin(T &a, const T &b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using P = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;
using vvi = vector<vi>;
using vvll = vector<vll>;

const ll MOD = 1e9 + 7;
const int INF = INT_MAX / 2;
const ll LINF = LLONG_MAX / 2;
const ld eps = 1e-9;


// edit

void solve() {
    ll R, X, Y;
    cin >> R >> X >> Y;
    ll norm = X * X + Y * Y;
    if (norm == R * R) {
        cout << 1 << endl;
    } else if (norm < R * R) {
        cout << 2 << endl;
    } else {
        ll k = 1;
        while (norm > k * k * R * R) {
            k++;
        }
        cout << k << endl;
    }
}


int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
//    std::ifstream in("input.txt");
//    std::cin.rdbuf(in.rdbuf());

    solve();


    return 0;
}

#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
#define Ma7moud_7amdy                 \
	ios_base::sync_with_stdio(false); \
	cin.tie(NULL);                    \
	cout.tie(NULL);
#define Open_Sesame Open()
#define all(v) ((v).begin()), ((v).end())
#define allr(v) ((v).rbegin()), ((v).rend())
#define watch(x) cout << #x << " = " << x << endl;
#define endl "\n"
#define double long double
#define INF 0x3f3f3f3f3f3f3f3fLL
const int dx[] = { 1, 0, -1, 0, 1, 1, -1, -1 };
const int dy[] = { 0, 1, 0, -1, 1, -1, 1, -1 };
typedef long long ll;
typedef unsigned long long ull;
void Open()
{
#ifndef ONLINE_JUDGE
	freopen("standard.in", "r", stdin);
	freopen("standard.out", "w", stdout);
#else
	//freopen("eliminating.in", "r", stdin);
	//freopen("standard.out", "w", stdout);
#endif
}
const ll mod = int(1e9 + 7), N = 500 + 5, oo = int(1e9), M = N * 104 * 2;
//"The secret of getting ahead is getting started". Mark Twain

//if you get WR, don't try to debug the code too much: think about another idea;
//don't be afraid of letters,letter G doesn't mean  the problem is hard;
//don't stuck in one problem after you gets alot WR ,just jump to the next one

int main()
{
	Ma7moud_7amdy;
	//Open_Sesame;
	ll r, x, y;
	cin >> r >> x >> y;

	double dis = sqrt(x * x + y * y);
	if (dis == r) {
		cout << 1 << endl;
	}
	else if (dis < r)cout << 2 << endl;
	else {
		ll cnt = ceil(dis / r);
		int add = 0;// (dis / r) != (ceil(dis / r) * r);
		cout << cnt + add << endl;
	}
}
//"There's a way to do it better - find it". Thomas A. Edison