
#include <iostream>
#include<string>
#include<cmath>
#include<algorithm>
#include<cctype>
#include<queue>
#include<deque>
#include<regex>
#include<stack>
#include<stdio.h>
#include<vector>
#include<set>
#include<map>
#include<iomanip>

// #include<atcoder/all>
// using namespace atcoder;

#define rep(i,n) for(int i=0;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define reve(i,n) for(int i=n-1;i>=0;i--)
#define vec(a,n) vector<long long> a(n,0);
#define ALL(a)  (a).begin(),(a).end()
#define F first //pairの一つ目の要素
#define S second //pairの二つ目の要素
#define MAX(x) *max_element(ALL(x)) //最大値を求める
#define MIN(x) *min_element(ALL(x)) //最小値を求める
typedef int long long ll;
using namespace std;
typedef pair<ll,ll> P;

typedef priority_queue<ll> PQ;
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
int dx8[8]={1,0,-1,0,1,1,-1,-1};
int dy8[8]={0,1,0,-1,1,-1,1,-1};
const ll MOD=1e9+7;
static const int MAX = 100;
static const int INF = (1<<23);

template<class T> T gcd(T a, T b){return b? gcd(b,a%b) : a;}
template<class T> T lcm(T a,T b){return a / gcd(a,b)*b;}
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

// vector<int> a(51,0);
// vector<vector<int> > tate(a,vector<int>(b)) ;

ll spp(ll cnt,ll dis , ll r){

    if (dis%r == 0 && dis >= r ){
        cnt = dis/r;
        return cnt;
    }
    else if(2*r >= dis ){
        cnt += 2;
        return cnt;
    }
    else{
        cnt = spp(cnt+1,dis-r,r);
    }
    return cnt;
}

int main(){
    ll r,x,y; cin >> r >> x >> y;
    double dis = sqrt(x*x+y*y);

    ll cnt = 0;

    
    // else if(dis < r){
    //     cnt = 2;
    // } 
    // else{
    //     cnt = spp(cnt,dis,r);
    // }

    cnt = ceil(double(dis/r));
    if(dis < r) cnt = 2;
    if(x == 0 && y == 0){
        cnt = 0;
    }
   
    cout << cnt << endl;
    return 0;   
}





#include <iostream>
#include <cstring>
#include <algorithm>
#include <vector>
#include <string>
#include <math.h>
#include <iomanip>
#include <limits>
#include <list>
#include <queue>
#include <tuple>
#include <map>
#include <stack>
#include <set>
#include <bitset>
#include <functional>
#include <cassert>

using namespace std;
 
int main() {
  long long int R;
  long long int X;
  long long int Y;
  cin >> R >> X >> Y;
  double Z;
  Z = sqrt(X*X + Y*Y);
  if(Z==R){
    cout << 1 << endl;
  }
  else if(Z<2*R){
    cout << 2 << endl;
  }
  else{
    cout << ceil(Z/R) << endl;
  }
}