Yaroslav has an array that consists of *n* integers. In one second Yaroslav can swap two neighboring array elements. Now Yaroslav is wondering if he can obtain an array where any two neighboring elements would be distinct in a finite time.

Help Yaroslav.
The first line contains integer *n* (1 ≤ *n* ≤ 100) — the number of elements in the array. The second line contains *n* integers *a*<sub class="lower-index">1</sub>, *a*<sub class="lower-index">2</sub>, ..., *a*<sub class="lower-index">*n*</sub> (1 ≤ *a*<sub class="lower-index">*i*</sub> ≤ 1000) — the array elements.
import itertools
n=int(input())
ai=list(map(int,input().split()))

if n==len(ai):
    if len(ai)==1:
        q="YES"
    for a, b in itertools.combinations(ai, 2):
        if a==b:
            q="NO"
        else:
            q="YES"

print(q)          



