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

#define fast ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define ll          long long
#define ull         unsigned long long
#define pb          push_back
#define pii         pair<int,int>
#define pll         pair<long,long>
#define vi          vector<int>
#define vll         vector<ll>
#define vii         vector<pii>
#define Mi          map<int,int>
#define mii         map<pii,int>
#define all(a)      (a).begin(),(a).end()
#define rall(a)      (a).rbegin(),(a).rend()
#define ff           first
#define ss           second
#define sz(x)       (int)x.size()
//#define endl        '\n'
#define mod        1000000007
//#define mod        998244353
#define rep(i,a,b)  for(int i=a;i<b;i++)
#define rem(i,a,b)  for(int i=a;i>b;i--)
#define mp(a,b)     make_pair(a,b)
#define INF         numeric_limits<ll>::max();
#define NINF        numeric_limits<ll>::min();
#define vvi(a,b,name)    vector<vector<int>> name(a,vector<int>(b,-1))
const long double pi=3.14159265359;

inline ll add(ll a, ll b, ll m)
{
    if ((a + b) >= m)
        return (a + b) % m;
    return a + b;
}

inline ll mul(ll a, ll b, ll m)
{
    if ((a * b) < m)
        return a * b;
    return (a * b) % m;
}

ll power(ll x, ll y, ll m)
{
    ll res = 1;
    x = x % m;
    if (x == 0)
        return 0;
    while (y > 0)
    {
        if (y & 1)
            res = (res * x) % m;
        y = y >> 1;
        x = (x * x) % m;
    }
    return res;
}

ll gcd(ll a, ll b)
{
    if (b == 0)
        return a;
    return gcd(b, a % b);
}

int main()
{fast;
 #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
 #endif
 int t=1,n;
 //cin>>t;
 while(t--)
 {double r,x,y;
  cin>>r>>x>>y;
  double d=sqrt(x*x+y*y);
  if(d<r){
    cout<<2;
  }
  else
  cout<<ceil(d/r);
 }
 return 0;
}

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
int main(){
  ll r,x,y;
  cin >> r >> x >> y;
  ll euqlid = x*x+y*y;
  if(euqlid<r*r){
    cout << 2 << endl;
    return 0;
  }
  ll i = 1;
  while(1){
    if(euqlid<=i*i*r*r) break;
    i++;
  }
  cout << i << endl;
}