a=list(map(str,input().split()))
n=a.index("?")
ans = ""
a[n]="1"
if a[1] == min(a) or a[1] == max(a):
    ans += "1"
a[n]="4"
if a[1] == min(a) or a[1] == max(a):
    ans += "4"
print(ans)