from collections import Counter
from operator import itemgetter

N=int(input())
C=Counter([input() for i in range(N)])

LIST=[]

for c in C:
    LIST.append([C[c],c])

A=[]
while LIST:
    LIST.sort(key=itemgetter(0),reverse=True)
    while LIST and LIST[-1][0]==0:
        LIST.pop()

    if LIST==[]:
        print("YES")
        break

    if A and A[-1]==LIST[0][1]:
        if len(LIST)==1:
            print("NO")
            break
        else:
            LIST[1][0]-=1
            A.append(LIST[1][1])
    else:
        LIST[0][0]-=1
        A.append(LIST[0][1])