import collections

N = int(input())
A = [input() for _ in range(N)]


_, cnts = zip(*collections.Counter(A).most_common())

if len(cnts) == 1:
    if cnts[0] == 1:
        print("YES")
    else:
        print("NO")
else:
    wk = 0
    for x in reversed(cnts):
        if wk != 0 and wk+1 < x:
            print("NO")
            break
        wk += x
    else:
        print("YES")