a = input()
b = a.split(' ')
c = []
m = 0
for i in range(1, len(b)):
    m = max(b.count(b[i]), b.count(b[i - 1]))
for i in b:
    if b.count(i) == m and c.count(i) == 0:
        c.append(int(i))
if len(b) != 1:
    res = max(c)
else: res = int(a)
print(res)