#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define forin(in) for(ll i=0; i<(ll)in.size(); i++) cin>>in[i]
#define forout(out) for(ll i=0; i<(ll)out.size(); i++) cout<<out[i]<<" "
#define rep(i, n) for(ll i=0; i<(n); i++)
#define rep_up(i, a, n) for (ll i = a; i < n; ++i)
#define rep_down(i, a, n) for (ll i = a; i >= n; --i)
#define P pair<ll, ll>
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
#define all(v) v.begin(), v.end()
#define fi first
#define se second
#define vvvll vector<vector<vector<ll>>>
#define vvll vector<vector<ll>>
#define vll vector<ll>
#define pqll priority_queue<ll>
#define pqllg priority_queue<ll, vector<ll>, greater<ll>>
constexpr ll INF = (1ll << 60);
constexpr ll mod = 1000000007;

int main() {
	long double R, X, Y; cin >> R >> X >> Y;
	long double d = sqrt(X*X+Y*Y);
	if(d == R) cout << 1 << endl;
	else if(d <= 2*R) cout << 2 << endl;
	else cout << ceil(d/R) << endl;
}
#include <bits/stdc++.h>
using namespace std;
using ll = int64_t;

int main(){
  double r,x,y;
  ll hosu = 0;
  cin >> r >> x >> y;
  if(sqrt(x * x + y * y) / r < 1){
    hosu = 2;
  }
  else{
    hosu = ceil(sqrt(x * x + y * y) / r);
  }
  cout << hosu;
}