#include <bits/stdc++.h>
using namespace std;
// const int maxn=1e5;
int ha[60] = { 0 };
int sumn(int n) {
    int sum = 0;
    while (n) {
        sum += n % 10;
        n /= 10;
    }
    return sum;
}
int main() {
    int n;
    cin >> n;
    long long ans = 0;
    for (int i = 1; i <= n; i++) {
        int k = sumn(i);
        ha[k]++;
    }
    for (int i = 0; i < 60; i++) {
        if (ha[i]) {
            ans += ha[i] * ha[i];
        }
    }
    cout << ans;
    //    cout<<sumn(10000);
    return 0;
}