a, b = [int(_) for _ in input().split()]

c = abs(a)
d = abs(b)

c = list(str(c))
d = list(str(d))

c = sorted(list(set(c)))
d = sorted(list(set(d)))

if 1 <= int(c[-1]) <= 9 and 1 <= int(d[-1]) <= 9 and len(c) == len(d) == 2:
    e = a * b
    print(e//10)
else:
    f = a * b
    if -99999999 <= f <= 99999999:
        print(f)
    else:
        print('E')