#pragma GCC optimize("O3")

#include <bits/stdc++.h>
using namespace std;
// #include <boost/multiprecision/cpp_int.hpp>
// using namespace boost::multiprecision;
// using cint = cpp_int;

#define fastio \
std::cin.tie(nullptr); \
std::ios::sync_with_stdio(false);

using ll = long long;
using ld = long double;

#define For(i, m, n)    for(int i = (m); (i) < (n); ++(i))
#define Rep(i, n)       For(i, 0, n)
#define Each(e, con)    for(auto e: con)
#define rEach(e, con)   for(auto &e: con)
#define crEach(e, con)  for(const auto &e: con)

#define All(con)        (con).begin(), (con).end()
#define Unique(con)     std::sort(All(con)); (con).erase(std::unique(All(con)), (con).end())
#define Reverse(con)    std::reverse(All(con))
#define Middle(con)     (con).begin() + ((con).end() - (con).begin()) / 2

template <class Ty1, class Ty2>
std::istream &operator>>(std::istream &is, std::pair<Ty1, Ty2> &arg)
{ is >> arg.first >> arg.second; return is; }
template <class Ty>
std::istream &operator>>(std::istream &is, std::vector<Ty> &arg)
{ rEach(e, arg) is >> e; return is; }
template <class Ty>
std::istream &operator>>(std::istream &is, std::vector<std::vector<Ty>> &arg)
{ rEach(sub, arg) { rEach(e, sub) { is >> e; }} return is; }

template <class Ty1, class Ty2>
std::istream &vecinput(std::vector<Ty1> &arg1, std::vector<Ty2> &arg2)
{ assert(arg1.size() == arg2.size());
auto sz = arg1.size(); Rep(i, (int)sz) std::cin >> arg1[i] >> arg2[i]; return std::cin; }
template <class Ty1, class Ty2, class Ty3>
std::istream &vecinput(std::vector<Ty1> &arg1, std::vector<Ty2> &arg2, std::vector<Ty3> &arg3)
{ assert(arg1.size() == arg2.size()); assert(arg2.size() == arg3.size());
auto sz = arg1.size(); Rep(i, (int)sz) std::cin >> arg1[i] >> arg2[i] >> arg3[i]; return std::cin; }
template <class Ty1, class Ty2, class Ty3, class Ty4>
std::istream &vecinput(std::vector<Ty1> &arg1, std::vector<Ty2> &arg2, std::vector<Ty3> &arg3, std::vector<Ty4> &arg4)
{ assert(arg1.size() == arg2.size()); assert(arg2.size() == arg3.size()); assert(arg3.size() == arg4.size());
auto sz = arg1.size(); Rep(i, (int)sz) std::cin >> arg1[i] >> arg2[i] >> arg3[i] >> arg4[i]; return std::cin; }

int main() {
fastio

    int r, x, y;
    cin >> r >> x >> y;

    double dist = hypot(x, y);

    int ans = 0;
    while(dist > 2 * r) {
        dist -= r;
        ++ans;
    }

    if(abs(dist - r) < 1e-9) cout << ans + 1 << endl;
    else cout << ans + 2 << endl;

    return 0;
}
#include<bits/stdc++.h>
using namespace std;

#define int long long 
#define vi vector<int>
#define pii pair<int,int> 
#define all(v) v.begin(),v.end()
#define pb push_back
#define ff first
#define ss second
#define max(a,b) (a>b ? a:b)
#define min(a,b) (a<b ? a:b)
 
void solve(){
	int r,x,y;
	cin>>r>>x>>y;
	int ans=1;
	int k=x*x+y*y;
	if(r*r>k){
		cout<<2;
		return;
	}
	while(k>(ans*r*ans*r)){
		ans++;
	}
	cout<<ceil(ans);
}

int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	// int t;cin>>t;while(t--)
	{
		solve();
	}
	return 0;
}