#include <bits/stdc++.h>
using namespace std;
// clang-format off
using ll = int64_t;
template <class T>
istream& operator>>(istream& is, vector<T>& v) {
    for (auto& a : v) cin >> a;
    return is;
}
template <class T>
istream& operator>>(istream& is, vector<pair<T, T>>& v) {
    for (auto& a : v) cin >> a.first >> a.second;
    return is;
}
template <class T>
istream& operator>>(istream& is, vector<tuple<T, T, T>>& v) {
    for (auto& a : v) {
        T a1, a2, a3;
        cin >> a1 >> a2 >> a3;
        a = {a1, a2, a3};
    }
    return is;
}
template <class T>
ostream& operator<<(ostream& os, vector<T>& v) {
    for (auto& a : v) os << a << " ";
    os << endl;
    return os;
}
template<class T>
bool chmin(T &a, T b) {
    if (a > b) { a = b; return true; } 
    return false;
}
template<class T>
bool chmax(T &a, T b) {
    if (a < b) { a = b; return true; } 
    return false;
}
#define all(v) begin(v), end(v)
#define TRC1(a) cout << #a ":" << a
#define TRC2(a, b) TRC1(a); cout << " "; TRC1(b)
#define TRC3(a, b, c) TRC2(a, b); cout << " "; TRC1(c)
#define TRC4(a, b, c, d) TRC3(a, b, c); cout << " "; TRC1(d)
using veci = vector<int>;
using vecll = vector<ll>;
using Pi = pair<int, int>;
using Ti = tuple<int, int, int>;
#define rep(i, n) for (int i = 0; i < n; i++)
#define fore(x, v) for (auto x : v)
const int IINF = INT32_MAX;
const ll LINF = INT64_MAX;
// cout << fixed << setprecision(15);
void solve();
int main() { cout << fixed << setprecision(15); solve(); return 0; }
// clang-format on

void solve() {
    double R, X, Y;
    cin >> R >> X >> Y;
    double d = sqrt(X * X + Y * Y);
    if (d == R) {
        cout << 1 << endl;
        return;
    }
    if (d <= 2 * R) {
        cout << 2 << endl;
        return;
    }

    ll ans = ceil(d / R);
    cout << ans << endl;
}

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

int main() {
 ll R,X,Y;
  cin>>R>>X>>Y;
 ll count=0;
 ll r=0;
  
 while(r<X*X+Y*Y){
   if(R*R>X*X+Y*Y){
   	count=2;
     break;
   }
 	count++;
   r=(count*R)*(count*R);
   
     
 }
  cout<<count<<endl;
}
