#include <iostream>
using namespace std;
int main() {
    int n;
    cin >> n;
    int ans1[50] = {}, ans2[50] = {};
    int i = 1;
    while (i <= n) {
        int sum = 0, temp = i;
        while (temp != 0) {
            sum += (temp % 10);
            temp /= 10;
        }
        ans1[sum]++;
        ans2[sum]++;
        i++;
    }
    int sum = 0;
    for (int j = 0; j < 50; j++) {
        sum += ans1[j] * ans2[j];
    }
    cout << sum;
}