Олимпиадный тренинг

Задача 7150. With a difference of 10


The number of each of the 40 classes of the school is known. Is it true that the largest class has 10 more students than the smallest? Display the word YES if the answer to the question is yes, or NO otherwise.

Input
The input line contains 40 integers, each number is not greater than 150.

Imprint
Print YES if the largest class has 10 more students than the smallest class. Otherwise, print NO.