s = ''.join(input().split())
ans = ''
for i in range(3):
    if s[i] == '?':
        t = s[0:i] + '1' + s[i + 1:]
        a = list(int(c) for c in t)
        if a[1] == min(a) or a[1] == max(a):
            ans += '1'
        t = s[0:i] + '4' + s[i + 1:]
        a = list(int(c) for c in t)
        if a[1] == min(a) or a[1] == max(a):
            ans += '4'
print(ans)