arr = []

a = 1
i = 0
maxx = -999
secondMax = -999

while a != 0:
    a = int(input())
    arr.append(a)
    i = i + 1

for x in range(0, i):
    if maxx < arr[x]:
        maxx = arr [x]

for x in range(0, i):
    if secondMax < arr[x] and arr[x] < maxx:
        secondMax = arr[x]


if secondMax == 0 or secondMax == -999:
    print(0)
else:
    print(secondMax)