sentence = input().split()
d = dict()
max_count = 0
for word in sentence:
    if word in d:
        d[word] += 1
    else:
        d[word] = 1
for word in d:
    if d[word] > max_count:
        max_count = d[word]
        max_word = word
    elif d[word] == max_count:
        max_word = min(word, max_word)
print(max_word)