import java.util.*;
public class Happy_Number_14
{
//isHappyNumber() will determine whether a number is happy or not
public static int isHappyNumber(int num)
{
int rem = 0, sum = 0;
//Calculates the sum of squares of digits
while(num > 0){
rem = num%10;
sum = sum + (rem*rem);
num = num/10;
}
return sum;
}
public static void main(String[] args)
{
Scanner sc=new Scanner(System.in);
System.out.println("Enter a number");
int num =sc.nextInt();
int result = num;
while(result != 1 && result != 4){
result = isHappyNumber(result);
}
//Happy number always ends with 1
if(result == 1)
System.out.println(num + " is a happy number");
//Unhappy number ends in a cycle of repeating numbers which contains 4
else if(result == 4)
System.out.println(num + " is not a happy number");
}
}