#include <iostream>
#include <stdio.h>
#include <string.h>
#define MAX_D 100
#define int long long

using namespace std;

int n;
int c[MAX_D];

int getsum(int x) {
    int ans = 0;
    while (x) {
        ans += x % 10;
        x /= 10;
    }
    return ans;
}

signed main() {
    scanf("%lld", &n);
    for (int i = 1; i <= n; i++) {
        c[getsum(i)]++;
    }
    int ans = 0;
    for (int i = 1; i < MAX_D; i++) {
        ans += c[i] * c[i];
    }
    printf("%lld\n", ans);
}