Taco Rearrangement

You are given an array arr consisting of elements that can only be -1, 0, or 1. Your task is to determine if it is possible to rearrange the array so that for every pair of adjacent elements, the following condition holds:

$$a_i + a_{i+1} \ge -1$$

If such a rearrangement exists, print YES; otherwise, print NO.

Note: In particular, if the array contains more than one occurrence of -1 and does not contain any 1, then it is impossible to avoid having two adjacent -1's whose sum is -2, which violates the condition.

inputFormat

The input consists of two lines:

• The first line contains a single integer n representing the length of the array.
• The second line contains n space-separated integers, each of which is -1, 0, or 1.

outputFormat

Output a single line containing either YES or NO based on whether a valid rearrangement exists.

## sample

5
1 -1 0 1 -1

YES

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