s = input()

n1,  n2 = s.split()

n1 = int(n1)

n2 = int(n2)

flag = True

if n1 < 0 or n1 > 9:

	flag = False

if n2 < 0 or n2 > 9:

	flag = False

if flag:

	print(n1 * n2)

else:

	print(-1)
N = list(map(int, input().strip().split()))

state=-1

if(N[0]>=1 and N[0] <=9 and N[1]>=1 and N[1] <=9):

  state=N[0]*N[1]

print(state)
s = input()
n1, n2 = s.split()
n1 = int(n1)
n2 = int(n2)
flag = True
if n1 < 0 or n1 > 9:
    flag = False
if n2 < 0 or n2 > 9:
    flag = False
if flag:
    print(n1 * n2)
else:
    print(-1)

N = list(map(int, input().strip().split()))
state = -1
if N[0] >= 1 and N[0] <= 9 and N[1] >= 1 and N[1] <= 9:
    state = N[0] * N[1]
print(state)

-s = input() -n1, n2 = s.split() -n1 = int(n1) -n2 = int(n2) -flag = True -if n1 < 0 or n1 > 9: -    flag = False -if n2 < 0 or n2 > 9: -    flag = False -if flag: -    print(n1 * n2) -else: -    print(-1) +N = list(map(int, input().strip().split())) +state = -1 +if N[0] >= 1 and N[0] <= 9 and N[1] >= 1 and N[1] <= 9: +    state = N[0] * N[1] +print(state)