Write a Perl palindrome check program. Do not use the reverse function. Do not use arrays or other libraries for this program. Please use low-level knowledge to solve that.

Sample Run 1: Enter in a 7 character phrase: 1111111

PALINDROME

2: Enter in a 7 character phrase: racecar

PALINDROME

3: Enter in a 7 character phrase: 1234321

PALINDROME

4: Enter in a 7 character phrase: 1234522

NOT

5: Enter in a 7 character phrase: abluent

NOT

6: Enter in a 7 character phrase: 123

ERROR: That is not a 7-character input.