l = list(map(str, input().split()))
x, y = [], []
for c in l:
    if c!='?':
        x.append(int(c))
        y.append(int(c))
    else:
        x.append(1)
        y.append(4)
ret = ''
if min(x)==x[1] or max(x)==x[1]:
    ret += '1'
if min(y)==y[1] or max(y)==y[1]:
    ret += '4'
print(ret)