// AtCoder Templete

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

#define rep(i, n) for (int i = 0; i < (n); i++)
#define rrep(i, n) for (int i = (n) - 1; i >= 0; i--)
#define loop(i, r, n) for (int i = (r); i < (n); i++)
#define lloop(i, r, n) for (int i = (r) - 1; i >= 0; i--)
#define all(in) in.begin(),in.end()
#define pb push_back
#define fi first
#define se second

template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }

using ui = unsigned int;
using ll = long long;
using ull = unsigned long long;
using dd = double;
using ldd = long double;

using pii = pair<int,int>;
using pll = pair<ll,ll>;
using pdd = pair<dd,dd>;

using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;

using vb = vector<bool>;
using vs = vector<string>;
using vdd = vector<dd>;
using vldd = vector<ldd>;

using pq = priority_queue<int, vector<int>, less<int>>; // 降順に取り出す
using pqq = priority_queue<int, vector<int>, greater<int>>; // 昇順に取り出す

// const ll MOD = 1e9+7;
const ll MOD = 998244353;
const int INF = 1e9;
const ll inf = 4e18;

const int MAX = 300300;
long long fac[MAX], finv[MAX], inv[MAX];

void COMinit() {
    fac[0] = fac[1] = 1; // 階乗
    finv[0] = finv[1] = 1; // 階乗の逆元
    inv[1] = 1; // 逆元
    for (int i = 2; i < MAX; i++){
        fac[i] = fac[i-1] * i % MOD;
        inv[i] = ( MOD - inv[MOD%i] * (MOD/i) % MOD ) % MOD;
        finv[i] = finv[i-1] * inv[i] % MOD;
    }
}
long long COM(int n, int k){
    if (n < 0 || k < 0 || n < k) return 0;
    return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}
long long PER(int n, int k) {
    if (n < 0 || k < 0 || n < k) return 0;
    return fac[n] * finv[n - k] % MOD;
}

ll modpow(ll a, ll n, ll p) {
    ll res = 1;
    while (n) {
        if (n & 1) res = res * a % p;
        a = a * a % p;
        n >>= 1;
    }
    return res;
}
ll modinv(ll a, ll p) { return modpow(a, p-2, p); }

vector<pair<ll,ll>> prime(ll n) {
    vector<pair<ll,ll>> res;
    for (ll i = 2; i * i <= n; i++) {
        if (n % i != 0) continue;
        ll count = 0;
        while (n % i == 0) { count++; n /= i; }
        res.push_back( make_pair(i,count) );
    }
    if (n != 1) res.push_back( make_pair(n,1) );
    return res;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    // cout << fixed << setprecision(10）<<  << endl;
    COMinit();
    
    /* write code under here */
    ll r, x, y; cin >> r >> x >> y;
  	if ( r * r == x * x + y * y ) {
      cout << 1 << endl;
      return 0;
    }
    for ( ll i = 2ll; i < 200200; i++) {
      	ll ii = i * r;
        if ( ii * ii >= x * x + y * y ) {
            cout << i << endl;
            return 0;
        }
    }
}
#include<bits/stdc++.h>
#define ll long long int
using namespace std;
int main()
{
    ll a,b,x,y;
    ll r;
    cin>>r>>a>>b;
    x=(a*a+b*b);
    ll t=ceil(sqrt((double)x));
    if(r==t) cout<<"1";
    else if(t<=(2*r)) cout<<"2";
    else cout<<ceil((double)t/r);
    
    return 0;
}