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.
index =int(input())
numbers = input().split()
lst = []
i=0

if index > 3:

    while i < index  :
        if (numbers[i],numbers[i+1])in lst :
                print('NO')
                exit()

        else:
            lst.append((numbers[i],numbers[i+1]))

        i+=2

print('YES')
