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


bool func(ll n, ll p, ll a, ll b){
    return (p * p < n * (p * a + b) + 1);
}


int main(){
    ll n;   cin >> n;

    ll ans = 0;
    for(ll a = 0; a < 10; ++a){
        for(ll b = 0; b < 10; ++b){
            if(a == b){
                continue;
            }
            ll p_min = max(a, b) + 1;
            if(!func(n, p_min, a, b)){
                continue;
            }
            ll ok = p_min, ng = 1000000001;
            while(abs(ok - ng) > 1){
                ll mid = (ok + ng) / 2;
                if(func(n, mid, a, b)){
                    ok = mid;
                }
                else{
                    ng = mid;
                }
            }
            ans += ok - p_min + 1;
        }
    }
    cout << ans << endl;

    return 0;
}