29.java

import java.io.*;
import java.util.*;
import java.lang.*;

public class Solution {

    public static void main(String[] args) throws IOException {
        BufferedReader f = new BufferedReader(new InputStreamReader(System.in));
        long n = Long.parseLong(f.readLine());

        Long output = (n - 1) * (n - 1);

        ArrayList < Integer > lists = new ArrayList < > ();
        boolean[] checker = new boolean[200001];

        Arrays.fill(checker, true);
        checker[0] = false;
        checker[1] = false;

        for (int i = 0; i < checker.length; i++) {
            if (checker[i]) {
                lists.add(i);
                for (int j = i * i; j < checker.length && j > 0; j *= i) {
                    checker[j] = false;
                }
            }
        }

        int[] prime = new int[lists.size()];

        for (int i = 0; i < prime.length; i++) prime[i] = lists.get(i);

        long num = 0;
        long base = 1;

        long largest = prime[0];
        long times = 1;
        while (largest * prime[0] <= n) {
            largest *= prime[0];
            times++;
        }

        boolean[][] check = new boolean[(int) times + 1][(int) n + 1];
        for (int k = 1; k < check.length; k++) {
            for (int j = 1; j < check[0].length; j++) {
                if (j != 0 && j != 1) check[k][j] = true;
            }
        }

        while (base * prime[0] <= n) {
            base *= prime[0];
            num++;
            long cden = num + 1;
            long cbase = base;

            while (cbase * prime[0] <= n) {
                cbase *= prime[0];

                for (int j = 2; cden * j <= num * n; j++) {
                    if (cden * j % num == 0) check[(int) cden][j] = false;
                }
                cden++;
            }


        }

        long[] sol = new long[check.length];

        for (int i = 1; i < sol.length; i++) {
            int cur = 0;
            for (int k = 1; k < check[0].length; k++) {
                if (k != 0 && k != 1 && !check[i][k]) sol[i]++;
            }
        }

        for (int i = 0; prime[i] <= Math.sqrt(n) + 1; i++) {
            long clargest = prime[i];
            int ctimes = 1;
            while (clargest * prime[i] <= n) {
                clargest *= prime[i];
                ctimes++;
            }
            for (int k = 1; k <= ctimes; k++) {
                output -= sol[k];
            }
        }
        System.out.println(output);
    }
}