import java.util.*;
import java.io.*;
import java.math.*;

class Solution {

    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int a = 0;
        int sum = 0;
        for (int i=2;i<Math.sqrt(n);i++) {
            if (n%i==0) {
                a++;
                break;
            }
        }
        if (a==0) {
            System.out.println(n*n);
        }
        else {
            n=n*n;
            while(n>0) {
                sum+=n%10;
                n-=n%10;
                n/=10;
            }
            System.out.println(sum);
        }
    }
}