Write a program which given a sequence without sentinel of naturals returns "SI" if in the sequence there
are at least five numbers of four digits with the first digit equal to the last digit, and "NO" otherwise.
Input A sequence of naturals without sentinel.
Output
A line with "SI" or "NO".
Observation
Input
1000 2000 3000 4000 5000 112 1001 2002
Output
NO
Input
10000 20000 1231 2342 100 2542 3453 4554 100 200 399 499 5555
Output
SI