#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int, int>;
struct fast_ios { fast_ios(){ cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(20); }; } fast_ios_;
const int INF = (int)1e9;
const ll INFL = (ll)1e18;
const int MOD = 1e9 + 7;
const double EPS = 1e-10;
int dx[]={0, 0, -1, 1};
int dy[]={1, -1, 0, 0};
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; }

long double solve(long double x1,long double y1,long double x2,long double y2)
{
    long double ans;

    ans = sqrt(pow(x1, 2) - 2 * x1 * x2 + pow(x2, 2) + (pow(y1, 2) - 2 * y1 * y2 + pow(y2, 2)));
    return ans;
}

int main()
{
    long double r, x, y, a,ans;
    int b;
    cin >> r >> x >> y;
    a = solve(0, 0, x, y);
    if (a == r)
        cout << 1 << endl;
    else if (a <= r + r)
        cout << 2 << endl;
    else
    {
        ans = (a / r);
        b = ceil(ans);
        cout << b << endl;
    }
    return 0;
}

#include<bits/stdc++.h> 
#include<stdlib.h>
#include<algorithm>
#include<cmath>
#include<map>
#include<set>
#include<deque>
#include<vector>
#include<string>
#include<cstring>
using namespace std;
#define FAST ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
#define ll long long

int main(){
	long double r,x,y;
	cin>>r>>x>>y;
	long double m=x*x+y*y;
    long double x1=m/2; 
	long double x0;                       
    do{
        x0=x1;                      
        x1=(x0+m/x0)/2;            
    }while(fabs(x0-x1)>=0.000000001);
    long double k=x1/r;
	x1=ceil(k);
	if(k<1) x1++;
	cout<<x1<<endl;
}