Task_2

from collections import Counter

s1 = []
s = list(input().lower().split())
for i in range(len(s)):
    s[i] = list(s[i])
    for j in range(len(s[i])):
        if s[i][j].isalpha() == False:
            s[i][j] = s[i][j].replace(s[i][j], '')
    s[i] = ''.join(s[i])
c = Counter(s)
c = dict(c.most_common(2))
for k in c.keys():
    s1.append(k)
print(s1[1])