#include<bits/stdc++.h>
#define lli long long
#define test int t;cin>>t;while(t--)
#define fast_io ios_base::sync_with_stdio(false);cin.tie(NULL)
#define  mod 1000000007
using namespace std;
void solve()
{
	double n , x , y , ans;
	cin >> n >> x >> y;
	lli dist = ceil(sqrt(x * x + y * y));
	if(dist == n)
	{
		ans = 1;
	}
	else
	{
		if(dist <= 2*n)
		{
			ans = 2;
		}
		else
		{
            ans = ceil(dist / (double)n);
		}
	}
	cout << ans;
}
int main()
{
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r" , stdin);
    freopen("output.txt", "w" , stdout);
#endif
    fast_io;
	//test
	{
		solve();
	}
	return 0;
}
#include<bits/stdc++.h>
using namespace std;
using LL=long long;
using P=pair<int,int>;
using T=tuple<LL,int,int,int>;
constexpr LL mod=1000000007;
constexpr LL inf=1e9;
constexpr double eps=1e-13;
constexpr double pi=3.141592653589;
int in(){
    int x;
    scanf("%d",&x);
    return x;
}
int main(){
    LL r=in(),x=in(),y=in();
    LL d=x*x+y*y,L=0,R=inf/r;
    if(r*r>d){
        cout<<2<<endl;
        return 0;
    }
    while(R-L>1){
        LL mid=(L+R)/2;
        if((r*mid)*(r*mid)>=d)R=mid;
        else L=mid;
    }
    cout<<R<<endl;
    return 0;
}