c = input().split()

# Find the position of '?'
replace_pos = -1
for i in range(3):
    if c[i] == '?':
        replace_pos = i
        break

valid = []

for candidate in ['1', '4']:
    new_list = c.copy()
    new_list[replace_pos] = candidate
    a, b, c_val = map(int, new_list)
    if (b > max(a, c_val)) or (b < min(a, c_val)):
        valid.append(candidate)

if len(valid) == 2:
    print("14")
else:
    print(''.join(valid))