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Mediummathloops

Perfect Number

Time limit 2 s · Memory 64 MBAcceptance: —Solved by: 0

Statement

You are given an integer n. Print YES if it is perfect, otherwise NO. A perfect number equals the sum of all its divisors except itself: for example, 28 = 1 + 2 + 4 + 7 + 14.

Examples

Example 1
Input
28
Output
YES
Example 2
Input
10
Output
NO

Constraints

  • 1 ≤ n ≤ 10^12
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