Special Number is:

• The number of digits is an even number
• The number and the reverse of the number are the same
• Include: 2,3,4

Example: 22,4444,4224,42422424

1<=i<=10^6

Output:

• input 1 should return output 22
• input 4 should return output 2222
• input 10 should return output 4224
• input 100 should return output 42422424

function generateSpecialNumber(n) {
}