C = input()
def is_kadomatsu(A):
    return not A[0] < A[1] < A[2] and not A[0] > A[1] > A[2]
ans = []
if is_kadomatsu(list(map(int, C.replace("?", "1").split()))):
    ans.append(1)
if is_kadomatsu(list(map(int, C.replace("?", "4").split()))):
    ans.append(4)
print(*ans, sep="")