#include <bits/stdc++.h>
#define rep(i, n, m) for (int i = (int)(n); i < (int)(m); i++)
#define long long ll
using namespace std;
using vi = vector<int>;
using vvi = vector<vi>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vc = vector<char>;
using vvc = vector<vc>;
using P = pair<int, int>;

int main(){
    double r, x, y; cin >> r >> x >> y;
        
    double dis = sqrt(x*x + y*y);

    int cnt = 0;

    while (dis > 2*r){
        dis -= r;
        cnt += 1;
    }

    if (dis == r){
        cnt += 1;
    }else if(dis == 0){
        cnt = 0;
    }else{
        cnt += 2;
    }

    cout << cnt << endl;
}
#include <bits/stdc++.h>
using namespace std;

#define REP(i,a,b) for(int i=a;i<=b;i++)
using LL = long long;

const int Nmax=2e5+9;
LL N,x,Up,Dn,Lv;
int cnt[9],digit,ans;

int main() {
    ios_base::sync_with_stdio(0);    cin.tie(0);
    cin>>N;
    cnt[1]=9;
    REP(i,2,6) cnt[i]=cnt[i-1]*10;
    x=N;
    while ((x/100)>0) {
        x/=100;      ++digit;
    }
    // cout<<digit<<" "<<x;
    REP(i,1,digit) ans+=cnt[i];
    Lv=1;
    REP(i,1,digit+1) Lv*=10;
    Up=N/Lv;    Dn=N%Lv;
    for (LL j=Lv/10;j<=Lv-1;++j) {
        if (j<Up || (j==Up && j<=Dn)) ++ans;
    }
    cout<<ans;
    return 0;
}
