#include <iostream>
#include <cstring>
using namespace std;
const int MAX = 1e5 + 5;
int f(int a) {
    int k = 0;
    do {
        k = k + a % 10;
        a = a / 10;
    } while (a > 0);
    return k;
}
int main() {
    int n;
    int a[100];
    memset(a, 0, sizeof(a));
    cin >> n;
    for (int i = 1; i <= n; i++) {
        a[f(i)]++;
    }
    int ans = 0;
    for (int i = 1; i <= 50; i++) ans += a[i] * a[i];
    cout << ans << endl;
    return 0;
}