# coding: utf-8
# yukicoder No.349 干支の置き物

from collections import Counter

eto = Counter()

N = int(input())

for _ in range(N):
    eto[input()] += 1

# 一番多い干支の数 - 1個の他の干支があればよい

if sum(eto.values()) >= 2 * max(eto.values()) - 1:
    print("YES")
else:
    print("NO")