s = input()
i = 1
n = ""
for j in range (0, len(s) - 1):
    if s[j] == s[j + 1]:
        i += 1
    else:
        n += s[j] + str(i)
        i = 1
n += s[-1] + str(i)
d = {}
for i in range(0, len(n) - 1, 2):
    d.update({n[i]: n[i + 1]})
print(d[max(d, key = d.get)])
print(max(d, key = d.get))