You are grading an arithmetic quiz. The quiz asks a student for the sum of the numbers. Determine if the student taking the quiz got the question correct.

입력 형식

The first and the only line of input contains a string of the form:</p>

a + b = c

It is guaranteed that a, b, and c are single-digit positive integers. The input line will have exactly 9 characters, formatted exactly as shown, with a single space separating each number and arithmetic operator.

출력 형식

Print, on a single line, YES if the sum is correct; otherwise, print NO.

예제 입력 1

1 + 2 = 3

예제 출력 1

YES

예제 입력 2

2 + 2 = 5

예제 출력 2

NO