#include <bits/stdc++.h>
using namespace std;

int main() {
  int64_t R, X, Y;
  cin >> R >> X >> Y;

  double distance = sqrt(X*X + Y*Y);
  int ans = ceil(distance / R);
  if (distance < R) ans = 2;

  cout << ans;
}

#include <bits/stdc++.h>
#if __has_include(<atcoder/all>)
    #include <atcoder/all>
    using namespace atcoder;
#endif
using namespace std;

//#define int long long
typedef long long ll;
typedef pair<int,int> P;
typedef pair<int,P> P1;
typedef pair<P,P> P2;
typedef vector<vector<int>> graph;
#define pu push
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define eps 1e-7
#define INF 1000000000
#define MOD 1000000007
#define MAXX 1.1529215e+18
#define _1 first
#define _2 second
#define rng(i,a,b) for(int i=int(a);i<int(b);i++)
#define rep(i,x) for(int i=0;i<x;i++)
#define repn(i,x) for(int i=1;i<=x;i++)
#define SORT(x) sort(x.begin(),x.end())
#define ERASE(x) x.erase(unique(x.begin(),x.end()),x.end())
#define POSL(x,v) (lower_bound(x.begin(),x.end(),v)-x.begin())
#define POSU(x,v) (upper_bound(x.begin(),x.end(),v)-x.begin())
#define all(x) x.begin(),x.end()
#define si(x) int(x.size())

template<class t,class u> bool chmax(t&a,u b){if(a<b){a=b;return true;}else return false;}
template<class t,class u> bool chmin(t&a,u b){if(b<a){a=b;return true;}else return false;}
 
template<class t> using vc=vector<t>;

template<class T> T gcd(T a, T b) { if (b == 0) return a; return gcd(b, a % b); }

template<class T>
T extgcd(T a, T b, T &x, T &y) {
    T d = a;
    if (b == 0) {
      x = 1;
      y = 0;
    } else {
      d = extgcd(b, a%b, y, x);
      y -= (a/b)*x;
    }
    return d;
}

template<class t,class u>
ostream& operator<<(ostream& os,const pair<t,u>& p){
	return os<<"{"<<p._1<<","<<p._2<<"}";
}
 
template<class t> ostream& operator<<(ostream& os,const vc<t>& v){
	os<<"{";
	for(auto e:v)os<<e<<",";
	return os<<"}";
}
 
template<class T>
void g(T &a){
	cin >> a;
}
template<class T>
void o(const T &a,bool space=false){
	cout << a << (space?' ':'\n');
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  ll R, X, Y;
  cin >> R >> X >> Y;
  ll ans = (X*X+Y*Y+R*R-1)/(R*R);
  // cout << ans << endl;
  ll i = 0;
  for (; i*i< ans; i++);
  if (i == 1) {
    if (X*X+Y*Y == R*R) {
      cout << 1 << endl;
    } else {
      cout << 2 << endl;
    }
  } else {
    cout << i << endl;
  }
}
