import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        boolean[] isNotPrimes = new boolean[n * 3 + 1];
        ArrayList<Integer> primes = new ArrayList<>();
      	ArrayList<Integer> bigPrimes = new ArrayList<>();
        for (int i = 2; i < isNotPrimes.length; i++) {
            if (!isNotPrimes[i]) {
              	if (i <= n)   {
              		primes.add(i);
                }
              	bigPrimes.add(i);
                for (int j = 2; j * i < isNotPrimes.length; j++) {
                    isNotPrimes[j * i] = true;
                }
            }
        }
      	int[] primeArray = new int[primes.size()];
      	for (int i = 0; i < primes.size(); i++) {
          	primeArray[i] = primes.get(i);
        }
        int[] bigPrimeArray = new int[bigPrimes.size()];
      	for (int i = 0; i < bigPrimes.size(); i++) {
          	bigPrimeArray[i] = bigPrimes.get(i);
        }
        HashMap<Integer, Integer> counts = new HashMap<>();
        for (int i = 1; i < primeArray.length; i++) {
            int x = primeArray[i];
            for (int j = i + 1; j < bigPrimeArray.length; j++) {
                int y = bigPrimeArray[j];
                counts.put(y - x, counts.getOrDefault(y - x, 0) + 1);
            }
        }
        long ans = 0;
        for (int i = 1; i < primeArray.length; i++) {
            int x = primeArray[i];
            for (int j = i + 1; j < bigPrimeArray.length; j++) {
                int y = bigPrimeArray[j];
                counts.put(y - x, counts.get(y - x) - 1);
            }
            for (int j = 0; j < i; j++) {
                int y = primeArray[j];
                ans += counts.getOrDefault(x + y, 0);
            }
        }
        System.out.println(ans);
    }
}

class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}