Problem:
 Score : 100 points    Problem Statement Having learned the multiplication table, Takahashi can multiply two integers between 1 and 9 (inclusive) together. He cannot do any other calculation.  Given are two integers A and B .  If Takahashi can calculate A \times B , print the result; if he cannot, print -1 instead.      Constraints  1 \leq A \leq 20  1 \leq B \leq 20  All values in input are integers.         Input Input is given from Standard Input in the following format:  A  B       Output If Takahashi can calculate A \times B , print the result; if he cannot, print -1 .        Sample Input 1 2 5      Sample Output 1 10  2 \times 5 = 10 .       Sample Input 2 5 10      Sample Output 2 -1  5\times 10 = 50 , but Takahashi cannot do this calculation, so print -1 instead.       Sample Input 3 9 9      Sample Output 3 81

Solution (Python):
A, B = map(int, input().split())

if A < 10 and B < 10:
    print(A*B)
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split());print([a*b,-1][a>9 or b>9])

Solution (Python):
a, b = map(int, input().split())
if 1 <= a <= 9 and 1 <= b <= 9:
    print(a * b)
else:
    print('-1')

Solution (Python):

def main():
    a,b = map(int,input().split())
    if a >= 10 or b >= 10:
        print(-1)
    else:
        print(a * b)


if __name__ == "__main__":
    main()

Solution (Python):
A, B = map(int, input().split())
if A >= 10 or B >= 10:
  print(-1)
else:
  print(A * B)

Solution (Python):
A, B = map(int, input().split())
print(A*B if 1<=A<=9 and 1<=B<=9 else "-1")

Solution (Python):
A,B = map(int, input().split())
if A < 10 and B < 10:
    print(A * B)
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split())
if 1<=a<=9 and 1<=b<=9:
  print(a*b)
else:
  print(-1)

Solution (Python):
a,b = map(int,input().split())
li = []
for i in range(1,10):
    for j in range(1,10):
        if i==a and j == b:
            print(a*b)
            exit()
print(-1)

Solution (Python):
import fileinput

a, b = map(int, input().split())

if a > 9 or b > 9:
    print("-1")
else:
    print(a * b)

Solution (Python):
a, b = map(int, input().split())
if a < 10 and b < 10:
	print(a * b)
else:
	print('-1')

Solution (Python):
a,b = map(str,input().split())
c = list(a)
d = list(b)
if len(c) == 1 and len(d) == 1:
    print(int(a)*int(b))
else:
    print(-1)

Solution (Python):
def ABC_144_A():
    A,B = map(int, input().split())
    if A<=9 and B<=9:
        print(A*B)
    else:
        print(-1)

if __name__ == '__main__':

    ABC_144_A()

Solution (Python):
def main():
    A, B = map(int,input().split())
    print( A * B if (A // 10 == 0) & (B // 10 == 0) else -1) 
    return 0
    
if __name__ == '__main__':
    main()

Solution (Python):
A,B=map(int,input().split())
print(A*B if (A<10 and B<10) else -1)

Solution (Python):
a, b = map(int, input().split())
ans = a * b
if a <= 9 and b <= 9:
    print(ans)
else:
    print(-1)

Solution (Python):
A,B = map(int, input().split())

if 1<= A <= 9 and 1<= B <= 9:
    print(A * B)
else:
    print("-1")

Solution (Python):
a, b = map(int, input().split())

if a == 0 or a >= 10 or b == 0 or b >= 10:
    print(-1)
else:
    print(a*b)

Solution (Python):
a,b=map(int,input().split())
if a>=10 or b>=10:
  print(str(-1)+"\n")
else:
  print(str(a*b)+"\n")

Solution (Python):
from collections import defaultdict, deque, Counter
from heapq import heappush, heappop
from itertools import permutations, accumulate, combinations, combinations_with_replacement
from math import sqrt, ceil, floor, factorial
from bisect import bisect_left, bisect_right
from copy import deepcopy
from operator import itemgetter
from functools import reduce


import sys
def I(): return int(input())
def Is(): return map(int, input().split())
def LI(): return list(map(int, input().split()))
def TI(): return tuple(map(int, input().split()))
def IR(n): return [I() for _ in range(n)]
def LIR(n): return [LI() for _ in range(n)]
def TIR(n): return [TI() for _ in range(n)]
def S(): return input()
def Ss(): return input().split()
def LS(): return list(input())
def SR(n): return [S() for _ in range(n)]
def SsR(n): return [Ss() for _ in range(n)]
def LSR(n): return [LS() for _ in range(n)]
sys.setrecursionlimit(10**6)
MOD = 10**9+7
INF = float('inf')


a, b = Is()
if a > 9 or b > 9:
    print("-1")
else:
    print(a*b)

Solution (Python):
a,b = map(int,input().split())
if a>9 or b>9: print(-1)
else: print(a*b)

Solution (Python):
A, B = map(int, input().split())
if A <= 9 and B <= 9:
  print(A*B)
else:
  print("-1")

Solution (Python):
A,B=map(int,input().split())
check=[1,2,3,4,5,6,7,8,9]
if A in check and B in check:
    print(A*B)
else:
    print("-1")

Solution (Python):

if __name__ == "__main__":
    A, B = input().split()
    if len(A) == 1 and len(B) == 1:
        print(int(A) * int(B))
    else:
        print("-1")

Solution (Python):
a , b = list(map(int,input().strip().split()))
print('-1' if (a>9 or b>9 or a<1 or b<1) else a*b)

Solution (Python):
A, B = map(int, input().split())
print(A*B) if (A<=9) & (B<=9) else print(-1)

Solution (Python):
a,b=map(int,input().split())
if a<10 and b<10:
    print(a*b)
else:
    print(-1)

Solution (Python):


A, B = map(int, input().split())
print(A * B if A < 10 and B < 10 else -1)

Solution (Python):
a,b=map(int,input().split())
print(a*b if 1<=a<=9 and 1<=b<=9 else "-1")

Solution (Python):


import sys
input= lambda: sys.stdin.readline().rstrip()
sys.setrecursionlimit(10**9)
def pin(type=int):return map(type,input().split())
def tupin(t=int):return tuple(pin(t))
def lispin(t=int):return list(pin(t))


def resolve():
    A,B=pin()
    if A>9 or B>9:print(-1);return
    print(A*B)

resolve()

Solution (Python):
a,b = map(int, input().split())

if(a > 9 or b > 9):
  print(-1)
else:
  print(a * b)

Solution (Python):
a,b=map(int,input().split())
if a<10 and b<10:
  print(a*b)
else:
  print('-1')

Solution (Python):
A, B = map(int, input().split())
if 1 <= A <= 9 and 1 <= B <= 9:
  print(A * B)
else:
  print(-1)

Solution (Python):
A, B = map(int, input().split())

if A < 10 and B < 10:
    print(A*B)
else:
    print(-1)

Solution (Python):
A, B = list(map(int,input().split()))
if A>0 and A<10 and B>0 and B<10:
    print(A*B)
else:
    print(-1)

Solution (Python):
a,b = map(int,input().split())
if (a >= 10)or(b >= 10):
    print(-1)
else:
    print(a * b)

Solution (Python):
def main():
    a, b = list(map(int, input().split()))
    if a < 10 and b < 10:
        print(a * b)
    else:
        print(-1)

if __name__ == '__main__':
    main()

Solution (Python):
a, b = map(int, input().split())
if 1 <= a <= 9 and 1 <= b <= 9:
    print(a*b)
else:
    print(-1)

Solution (Python):

A, B = map(int, input().split())
print(A*B if A<10 and B<10 else "-1")

Solution (Python):
a,b=map(int,input().split())
if 1<=a<=9 and 1<=b<=9:
    print(a*b)
else:
    print("-1")

Solution (Python):
A, B = map(int, input().split())
if A <= 9 and B <= 9:
    print(A * B)
else:
    print(-1)

Solution (Python):
A, B = input().split()
print(int(A)*int(B) if len(A) == len(B) == 1 else -1)

Solution (Python):
a,b,=map(int,input().split())
if a>=10 or b>=10:
    print(-1)
else:
    print(a*b)

Solution (Python):
A, B = map(int, input().split())
if A <= 9 and B <= 9:
    print(A*B)
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split())

if 1<=a<=9 and 1<=b<=9:
  print(a*b)
else:
  print(-1)

Solution (Python):
A,B = map(int,input().split())
if A>9 or B>9:
    print(-1)
else:
    print(A*B)

Solution (Python):
a,b = map(int,input().split())

if 1<=a<=9 and 1<=b<=9:
  print(a*b)
  
else:
  print("-1")

Solution (Python):
a, b = map(int, input().split())

if a < 10 and b < 10:
    print(a * b)
else:
    print(-1)

Solution (Python):
N, M = map(int, input().split())
print('-1' if N>9 or M>9 else N*M)

Solution (Python):
def main():
    a, b = map(int, input().split())
    if a < 10 and b < 10:
        print(a*b)
    else:
        print(-1)


main()

Solution (Python):
A,B = map(int,input().split())
if 1<=A<=9 and 1<=B<=9:
    print(A*B)
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split())
if a>9 or b>9:
    print(-1)
else:
    print(a*b)

Solution (Python):
a,b=map(int,input().split())
if a<=9 and b<=9:
    print(a*b)
else:
    print(-1)

Solution (Python):
A,B=map(int,input().split(" "))

print(A*B if 1<=A<=9 and 1<=B<=9 else -1)

Solution (Python):
A,B = map(int,input().split())

if A<=9 and B<=9:
  print(A*B)
else:
  print(-1)

Solution (Python):
a, b = map(int, input().split())
print(a * b if a < 10 and b < 10 else -1)

Solution (Python):
A,B=map(int,input().split())
if A<=9 and B<=9:
  print(A*B)
else:
  print(-1)

Solution (Python):
a,b=map(int,input().split())
if a<=9 and b<=9:
    print(a*b)
else:
    print(-1)

Solution (Python):
A, B = input().split()

if int(A) <= 9 and int(B) <= 9:
    print(int(A) * int(B))
else:
    print("-1")

Solution (Python):
A, B = map(int, input().split())

if 1 <= A <= 9 and 1 <= B <= 9:
    print(A * B)
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split());print(-1 if a>9 or b>9 else a*b)

Solution (Python):
a, b = map(int, input().split())
if a <= 9 and b <= 9:
  print(a * b)
else:
  print(-1)

Solution (Python):
A, B = map(int, input().split())
if A>=10 or B>=10:
    print('-1')
    exit()
else:
    print(A*B)

Solution (Python):
A,B = input().split()

if len(A)==2 or len(B)==2:
    print(-1)
    exit(0)

print(int(A)*int(B))

Solution (Python):
A,B = map(int,input().split())
print(A*B) if A <=9 and B <=9 else print('-1')

Solution (Python):
A,B=map(int,input().split())
if A<10 and B<10:
    print(A*B)
else:
    print(-1)

Solution (Python):

"""
Created on Sun May  3 18:07:38 2020

@author: Kanaru Sato
"""

a,b = list(map(int, input().split()))

if a >= 10 or b >= 10:
    print("-1")
else:
    print(a*b)

Solution (Python):
a,b = map(int,input().split())
ans = a * b
if a > 9 or b > 9: ans = -1
print(ans)

Solution (Python):
a,b=map(int,input().split())
print(a*b if a<=9 and b<=9 else '-1')

Solution (Python):
a, b = map(str,input().split())

if len(a)==len(b)==1:
    print(int(a) * int(b))

else:
    print(-1)

Solution (Python):
A, B = map(int, input().split())

if A < 10 and B < 10:
  print(A*B)
else:
  print(-1)

Solution (Python):
a,b=map(int,input().split())
if 1<=a<=9 and 1<=b<=9:
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split())
if 1<=a<=9 and 1<=b<=9:
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split())
if 1<=a<=9 and 1<=b<=9:
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split())
if 1<=a<=9 and 1<=b<=9:
    print(a*b)
else:
    print(-1)

Solution (Python):
A, B = map(int, input().split())
if A <= 9 and B <= 9:
  print(A*B)
else:
  print(-1)

Solution (Python):
a, b = map(int, input().split())

if a > 9 or b > 9:
    print(-1)
else:
    print(a*b)

Solution (Python):
x,y=map(int,input().split())
if x<10 and y<10:
	print(x*y)
else:
	print(-1)

Solution (Python):
a, b = map(int, input().split())
print(-1 if a not in range(1, 10) or b not in range(1, 10) else a*b)

Solution (Python):
a,b=map(int,input().split())
if a<10 and b<10:
    print(a*b)
else:
    print(-1)

Solution (Python):
A, B= map(int,input().split())
if A < 10 and B < 10:
    print(A*B)
else:
    print(-1)

Solution (Python):


a,b=(int(x) for x in input().split())

if a<10 and b<10:
    print(a*b)
else:
    print(-1)

Solution (Python):
a, b = input().split()

if len(a) == 1 and len(b) == 1:
    a = int(a)
    b = int(b)
    print(a * b) 
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split())

if a>9 or b>9:
    print(-1)
else:
    print(a*b)

Solution (Python):
a, b = map(int, input().split())
if 1 <= a <= 9 and 1 <= b <= 9:
    print(a*b)
else:
    print('-1')

Solution (Python):
a,b=map(int,input().split())
if a<10 and b<10:
  print(a*b)
else:
  print(-1)

Solution (Python):
a, b = map(int, input().split())
print(a * b if a < 10 and b < 10 else -1)

Solution (Python):
if __name__ == '__main__':
    a, b = map(int, input().split())
    if 1 <= a <= 9 and 1 <= b <= 9:
        print(a * b)
    else:
        print(-1)

Solution (Python):

a,b=map(int,input().split())

if 1<=a<=9 and 1<=b<=9:
    print(a*b)
else:
    print(-1)

Solution (Python):


def main():
    A, B = map(int, open(0).read().split())
    if (A < 10 and B < 10):
        print(A * B)
    else:
        print('-1')


main()

Solution (Python):
a,b = map(int,input().split())

if a<10 and b<10:
  print(a*b)
  
else:
  print('-1')

Solution (Python):
A, B = map(int, input().split())

if A < 10 and B < 10:
    print(A*B)
else:
    print(-1)

Solution (Python):
a, b = map(int, input().split())
if a>=10 or b>=10:
    print("-1")
else:
    print(a*b)

Solution (Python):
def main():
    a, b = map(int, input().split())
    if a <= 9 and b <= 9:
        print(a*b)
    else:
        print(-1)


if __name__ == "__main__":
    main()

Solution (Python):
a,b=map(int,input().split())
if len(str(a))>1 or len(str(b))>1:
	print("-1")
else:
	print(a*b)

Solution (Python):
def judge99(x):
    if x <= 9:
        return True
    else:
        return False

a, b = map(int,input().split())

if judge99(a) and judge99(b):
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split())
print(a*b if 1<=a<=9 and 1<=b<=9 else -1)

Solution (Python):
A, B = map(int, input().split())

if 1 <= A <= 9 and 1 <= B <= 9:
  print(A * B)
else:
  print(-1)

Solution (Python):
a,b = map(int,input().split())
if 10 > b and 10 > a:
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b = map(int,(input().split()))
ans=0

if a<=9 and b<=9:
  ans += a*b
  print(ans)
else:
  print(-1)

Solution (Python):
a, b = map(int, input().split())
ans = '-1'
if a < 10 and b < 10:
  ans = a*b
print(ans)

Solution (Python):
a,b=map(int,input().split())
print(a*b if a<10 and b<10 else -1)

Solution (Python):
a, b = map(int, input().split())
print(a * b if a <= 9 and b <= 9 else -1)

Solution (Python):






import sys
input = sys.stdin.readline

import math
from collections import deque
from fractions import gcd
from functools import lru_cache






MOD = 10**9+7
INF = float('inf')






def inputI(): return int(input().strip())
def inputS(): return input().strip()
def inputIL(): return list(map(int,input().split()))
def inputSL(): return list(map(str,input().split()))
def inputILs(n): return list(int(input()) for _ in range(n))
def inputSLs(n): return list(input().strip() for _ in range(n))
def inputILL(n): return [list(map(int, input().split())) for _ in range(n)]
def inputSLL(n): return [list(map(str, input().split())) for _ in range(n)]


def inv(n): return pow(n, MOD-2, MOD)


kaijo_memo = []
def kaijo(n):
  if(len(kaijo_memo) > n):
    return kaijo_memo[n]
  if(len(kaijo_memo) == 0):
    kaijo_memo.append(1)
  while(len(kaijo_memo) <= n):
    kaijo_memo.append(kaijo_memo[-1] * len(kaijo_memo) % MOD)
  return kaijo_memo[n]

gyaku_kaijo_memo = []
def gyaku_kaijo(n):
  if(len(gyaku_kaijo_memo) > n):
    return gyaku_kaijo_memo[n]
  if(len(gyaku_kaijo_memo) == 0):
    gyaku_kaijo_memo.append(1)
  while(len(gyaku_kaijo_memo) <= n):
    gyaku_kaijo_memo.append(gyaku_kaijo_memo[-1] * pow(len(gyaku_kaijo_memo),MOD-2,MOD) % MOD)
  return gyaku_kaijo_memo[n]

def nCr(n,r):
  if(n == r):
    return 1
  if(n < r or r < 0):
    return 0
  ret = 1
  ret = ret * kaijo(n) % MOD
  ret = ret * gyaku_kaijo(r) % MOD
  ret = ret * gyaku_kaijo(n-r) % MOD
  return ret


def factorization(n):
    arr = []
    temp = n
    for i in range(2, int(-(-n**0.5//1))+1):
        if temp%i==0:
            cnt=0
            while temp%i==0:
                cnt+=1
                temp //= i
            arr.append([i, cnt])
    if temp!=1:
        arr.append([temp, 1])

    if arr==[]:
        arr.append([n, 1])
    return arr


def lcm(a, b):
    return a * b // gcd (a, b)





a,b = inputIL()

if  a<10 and b<10:
  print(a*b)
else:
  print(-1)

Solution (Python):
(A,B)=input().split()
(A,B)=(int(A),int(B))
if 1<=A<=9 and 1<=B<=9:
  print(A*B)
else:
  print(-1)

Solution (Python):
a, b = map(int, input().split())
if a <= 9 and b <= 9:
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b = map(int,input().split())

if 1 <= a <= 9 and 1 <= b <= 9:
	print(a * b)
else:
	print('-1')

Solution (Python):
a, b = map(int, input().split())
print(a * b) if a < 10 and b < 10 else print(-1)

Solution (Python):
A,B=map(int,input().split())
if 10>A>0 and 10>B>0:
    print(A*B)
else:
    print(-1)

Solution (Python):
A,B = map(int, input().split())

if (A>=1)and(A<=9) and (B>=1) and (B<=9):
  print(A * B)
else:
  print(-1)

Solution (Python):
A,B=map(int, input().split())
if (A<=9) & (B<=9):
    print(A*B)
else:
    print(-1)

Solution (Python):
A, B = (int(x) for x in input().split())
if A>=1 and A <=9 and B >= 1 and B <= 9:
  print(A*B)
else:
  print(-1)

Solution (Python):
a,b = map(int,input().split())
print(a*b if(a<10 and b<10) else -1)

Solution (Python):
a,b=map(int,input().split())
if a<=9 and b<=9:
  print(a*b)
else:
  print("-1")

Solution (Python):
a, b = map(int, input().split())
if 1 <= a and 1<=b and a <= 9 and b <= 9:
  print(a*b)
else:
  print(-1)

Solution (Python):
A,B = map(int,input().split())
if 0<A<10 and 0<B<10:
    print(A*B)
else:
    print(-1)

Solution (Python):
a, b = map(int, input().split())
print(a*b if 0<a<10 and 0<b<10 else -1)

Solution (Python):
n,m = (int(x) for x in input().split())
if n <= 9 and m <= 9:
  print(n*m)
else:
  print(-1)

Solution (Python):
A,B = map(int, input().split())
print(A*B if A<=9 and B<=9 else '-1')

Solution (Python):
A, B = list(map(int, input().split()))

if A >= 10 or B >= 10:
    print("-1")
else:
    ans = A * B
    print(ans)

Solution (Python):
a,b = map(int,input().split())
if a < 10 and b < 10:
  print(a*b)
else:
  print("-1")

Solution (Python):
a,b=map(int,input().split())
print(-1if a>9or b>9 else a*b)

Solution (Python):
a,b=map(int,input().split())
if 0<a<10 and 0<b<10:print(a*b)
else: print('-1')

Solution (Python):
def main():
    A, B = map(int, input().split())
    if A <= 9 and B <= 9:
        print(A*B)
    else:
        print(-1)
if __name__ == "__main__":
    main()

Solution (Python):
x, y = map(int, input().split())
print(x*y if x <= 9 and y <= 9 else -1)

Solution (Python):
import sys
a, b = map(int, sys.stdin.readline().split())
if a <= 9 and b <= 9:
  print(a*b)
else:
  print(-1)

Solution (Python):
import os

def main():
	a,b = map(int, input().split())
	if a >= 10 or b >= 10:
		print(-1)
	else:
		print(a*b)


if __name__ == "__main__":
	main()

Solution (Python):
a, b = map(int, input().split())
if a <= 9 and b<=9:
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b=[int(i)for i in input().split()]
if a<10 and b<10:
  print(a*b)
else:
  print('-1')

Solution (Python):
a, b = map(int, input().split())
print(a * b if (a < 10 and b < 10) else -1)

Solution (Python):
A, B = map(int, input().split())

if A < 10 and B < 10:
    print (A * B)
else:
    print (-1)

Solution (Python):
a, b = map(int, input().split())
if a > 9 or b > 9:
    print(-1)
else:
    print(a*b)

Solution (Python):
A,B=input().split()
print(int(A)*int(B) if len(A)==1&len(B)==1 else -1)

Solution (Python):
a,b=map(int,input().split());print(a*b if a<10 and b<10 else -1)

Solution (Python):
a,b = map(int,input().split())
if a>= 10 or b>=10:
  print(-1)
else:
  print(a*b)

Solution (Python):
a, b = map(int, input().split())
if a <= 9 and b <= 9:
    print(a * b)
else:
    print(-1)

Solution (Python):
a,b = map(int, input().split())
if a > 9 or b > 9:
    print(-1)
else:
    print(a*b)

Solution (Python):
a, b = map(int,input().split())
if a<=9 and b<=9:
  print(a*b)
else:
  print('-1')

Solution (Python):
x = input().split()
a = int(x[0])
b = int(x[1])
if a <= 9 and b <= 9:
  print(a * b)
else:
  print('-1')

Solution (Python):
a, b = map(int, input().split())
if a > 9 or b > 9:
    print(-1)
    exit()
print(a * b)

Solution (Python):
a,b = map(int, input().split())
if a>=10 or b>=10:
  print(-1)
else:
  print(a*b)

Solution (Python):
def main():
    import sys
    input = sys.stdin.readline
    sys.setrecursionlimit(10**7)
    from collections import Counter, deque
    
    from itertools import combinations, permutations, accumulate, groupby, product
    from bisect import bisect_left,bisect_right
    from heapq import heapify, heappop, heappush
    from math import floor, ceil
    

    
    

    a, b = map(int, input().split())
    if a>=10 or b>=10:
        print(-1)
    else:
        print(a*b)

if __name__ == '__main__':
    main()

Solution (Python):
a,b=map(int,input().split())
if a<10 and b<10:
  print(a*b)
else:
  print(-1)

Solution (Python):
A, B = map(int, input().split())

if A > 9 or A <1 or B > 9 or B < 1:
    print(-1)
else:
    print(A*B)

Solution (Python):
a, b = map(int, input().split())
print(a*b if 1<=a<=9 and 1<=b<=9 else '-1')

Solution (Python):
a,b =map(int, input().split())

if a//10>0 or b//10>0:
  print(-1)
else:
  print(a*b)

Solution (Python):
m, n = map(int, input().split())

ret = m*n
if (m > 9) or (n > 9):
    ret = -1
print(ret)

Solution (Python):
a, b = map(int, input().split())
if a >= 10 or b >= 10:
    print("-1")

else:
    print(a*b)

Solution (Python):
A, B = map(int,input().split())
if A<10 and B<10:
    print(A*B)
else:
    print(-1)

Solution (Python):
a, b = [int(x) for x in input().split()]
ans = a * b if a <= 9 and b <= 9 else -1
print(ans)

Solution (Python):
a,b = map(int,input().split())
if 1<= a <= 9 and 1 <= b <= 9:
    print(int(a*b))
else:
    print(int(-1))

Solution (Python):
A, B = (int(x) for x in input().split())

if A > 9 or B > 9:
    print(-1)
else:
    print(A*B)

Solution (Python):
A, B = map(int, input().split())

if A > 9:
	print(-1)
elif B > 9:
	print(-1)
else:
	print(A*B)

Solution (Python):
a, b = map(int, input().split())
if 1 <= a <= 9 and 1 <= b <= 9:
    print(a*b)
else:
    print(-1)

Solution (Python):
x, y = map(int, input().split())
if x > 9 or y > 9:
  print(-1)
else:
  print(x*y)

Solution (Python):
line = input()
a, b = line.split(" ")
a = int(a)
b = int(b)

if a <= 9 and b <= 9:
    print(a * b)
else:
    print(-1)

Solution (Python):
A, B = map(int,input().split())
if A < 10 and B < 10:
    print(A*B)
else:
    print(-1)

Solution (Python):
a,b = map(int,input().split())

if a>= 10 or b >= 10:
    print(-1)
else :
    print(a*b)

Solution (Python):
A,B=[int(x) for x in input().rstrip().split()]
if 1<=A and A<=9 and 1<=B and B<=9:
  print(A*B)
else:
  print(-1)

Solution (Python):
A,B = map(int,input().split())
if 1<=A<=9 and 1<=B<=9:
  print(A*B)
else:
  print("-1")

Solution (Python):
a, b = map(int, input().split())

if 0 < a < 10 and 0 < b < 10:
    print(a*b)
else:
    print(-1)

Solution (Python):
A, B = map(int, input().split())
print(A*B if A<10 and B<10 else -1)

Solution (Python):
a, b = map(int, input().split())
print(a * b if 1 <= a <= 9 and 1 <= b <= 9 else -1)

Solution (Python):

a, b = map(int, input().split())

if (a >= 10 or b >=10):
  print("-1")
else:
  print(a*b)

Solution (Python):
a,b = map(int, input().split())
if(1<=a<=9 and 1<=b<=9):
  print(a*b)
else:
  print(-1)

Solution (Python):
n, m = map(int, input().split())
if 1 <= n <= 9 and 1 <= m <= 9:
    print(n * m)
else:
    print(-1)

Solution (Python):
A, B =map(int, input().split())

if 1 <= A <= 9 and 1 <= B <= 9:
    print(A * B)
else:
    print("-1")

Solution (Python):
a,b=map(int,input().split())
if a<10 and b<10:
    print(a*b)
else:
    print(-1)

Solution (Python):


import sys
import math
import time

import collections
from collections import deque
from collections import Counter
import queue
import copy
import bisect
import heapq
import itertools

def comb(n, k, mod):
    ret = 1
    for i in range(1, k + 1):
        ret = ret * (n - i + 1) % mod
        ret = ret * pow(i, mod - 2, mod) % mod
    return ret








A, B = map(int,input().split())
ans = A * B
if(A>9 or B>9):
    print(-1)
else:
    print(ans)

Solution (Python):
a, b=map(int,(input().split()))
		
if a <= 9 and b <= 9:
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split())
if a<=9 and b<=9:
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b=map(int,input().split())
if a<10 and b<10:
  print(a*b)
else:
  print('-1')

Solution (Python):
a, b = map(int, input().split())

if a >= 10 or b >= 10:
    print(-1)
else:
    print(a*b)

Solution (Python):
A,B = map(int,input().split())
if 1<=A<=9 and 1<=B<=9:
    print(A*B)
else:
    print(-1)

Solution (Python):
a,b = map(int,input().split())

if a>9 or b>9:
  print(-1)
else:
  print(a*b)

Solution (Python):
a, b = list(map(int, input().split()))
print(a * b) if len(str(a)) == 1 and len(str(b))==1 else print(-1)

Solution (Python):
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians
from itertools import accumulate, permutations, combinations, product, groupby
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from fractions import gcd
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

A, B = MAP()
print(A*B if 1<=A<10 and 1<=B<10 else -1)

Solution (Python):
x = input()
a = int(x.split()[0])
b = int(x.split()[1])

if (a >= 1 and a <= 9) and (b >= 1 and b <= 9):
    print( a * b )
else:
    print('-1')

Solution (Python):
import math
import fractions
import sys
import itertools
import numpy as np
from collections import Counter

def input1():
	return int(input())


def input2():
	return map(int,input().split())


def input_array():
	return list(map(int,input().split()))

def keta(N):
	return len(str(N))



a,b=input2()

if len(str(a))==1 and len(str(b))==1:
	print(a*b)
else:
	print(-1)

Solution (Python):
a,b=map(int,input().split())

if a>9 or b>9:
  print("-1")
else:
  print(a*b)

Solution (Python):
A, B = map(int,input().split())
print(A*B if A<=9 and B<=9 else -1)

Solution (Python):
a,b = map(int, input().split())
if (a > 9 or b > 9):
    print(-1)
else:
    print(a*b)

Solution (Python):
a, b = map(int, input().split())
if a >= 10 or b >= 10:
  print(-1)
else:
  print(a*b)

Solution (Python):
a = list(map(int,input().split()))
if a[0] >9 or a[1]>9:
    print(-1)
else:print(a[0]*a[1])

Solution (Python):
a,b=map(int,input().split())

if (1<=b<=9 and 1<=a<=9):
    print(a*b)
else:
    print(-1)

Solution (Python):
A,B=map(int, input().split())
flag=0
if A>9:
  flag=1
if B>9:
  flag=1
if flag==0:
  print(A*B)
else:
  print(-1)

Solution (Python):
a, b = map(int, input().split())
 
if 0<a<10 and 0<b<10:
  print(a*b)
else:
  print(-1)

Solution (Python):
A,B = map(int,input().split())
if(A <= 9 and B <= 9):
  print(str(A * B))
else:
  print("-1")

Solution (Python):
a, b = map(int, input().split())
if 1 <= a <= 9 and 1 <= b <= 9:
    print(a*b)
else:
    print(-1)

Solution (Python):
A, B = map(int, input().split())
L = A*B
if L > 81 or A > 9 or B > 9:
    print("-1")
else:
    print(L)

Solution (Python):
a,b=map(int,input().split())
if a<=9 and b<=9:
    print(a*b)
else: 
    print(-1)

Solution (Python):
a,b = map(int, input().split())
if a<10 and b<10:
    print(a*b)
else: print(-1)

Solution (Python):


a, b = map(int, input().split())

if a < 10 and b < 10:
    print(a * b)
else:
    print("-1")

Solution (Python):
A,B = map(int,input().split())

if A <= 9 and A >= 1 and B <= 9 and B >= 1:
    print(A*B)
else:
    print(-1)

Solution (Python):

import sys
import numpy as np


def solve(A: int, B: int):
    if (A>0 and A<10) and (B>0 and B<10):
        print(A*B)
    else:
        print(-1)
    return



def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    A = int(next(tokens))  
    B = int(next(tokens))  
    solve(A, B)

if __name__ == '__main__':
    main()

Solution (Python):
def main():
    a, b = map(int, input().split())
    if a < 10 and b < 10:
        print(a * b)
    else:print(-1)

if __name__ == "__main__":
    main()

Solution (Python):
a,b = map(int, input().split())

if a>=10 or b>=10 :
    print("-1")
else:
    print(a*b)

Solution (Python):
icase=0
if icase==0:
    a,b=map(int,input().split())
    if a<=9 and b<=9:
        print(a*b)
    else:
        print(-1)

Solution (Python):
a, b = input().split()
a_int = int(a)
b_int = int(b)

if a_int > 9 or b_int > 9:
    print('-1')
else:
    print(a_int*b_int)

Solution (Python):
a,b=map(int,input().split())
if a<10 and a>0 and b<10 and b>0:
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b = map(int,input().split())
if a>=1 and a<=9 and b>=1 and b<=9:
  print(a*b)
else:
  print(-1)

Solution (Python):
import sys
input = sys.stdin.readline

A, B = map(int, input().split())

print(-1) if A > 9 or B > 9 else print(A * B)

Solution (Python):
A,B=map(int,input().strip().split())

if A<10 and B<10:
    print(A*B)
else:
    print(-1)

Solution (Python):
inp = list(map(int, input().split()))
a, b = inp[0], inp[1]
if (a<10) and (b<10): print(a*b)
else: print(-1)

Solution (Python):
a,b = map(int,input().split())

if a<=9 and b<=9:
	print(a*b)
else :
	print(-1)

Solution (Python):
a,b=map(int,input().split())
if 1<=a<=9 and 1<=b<=9:
    print(a*b)
else:
    print(-1)

Solution (Python):
a, b = map(int, (input().split()))
print(a * b if a <= 9 and b <= 9 else -1)

Solution (Python):
A, B = map(int, input().split())
if A < 10 and B < 10:
  print(A*B)
else:
  print("-1")

Solution (Python):
A, B = map(int, input().split())

if A < 10 and B < 10:
  print(A * B)
else:
  print(-1)

Solution (Python):
a,b=map(int,input().split())

if a>=1 and a<=9 and b>=1 and b<=9:
  print(a*b)
else:
  print(-1)

Solution (Python):
A,B = map(int, input().split())
if A <= 9 and B <= 9:
    ans = A*B
else: ans = "-1" 
print(ans)

Solution (Python):
a = list(map(int, input().split()))

if a[0] > 9 or a[1] > 9:
  print(-1)
else:
  print(a[0] *a[1])

Solution (Python):
a, b = map(int, input().split())

if a >= 10 or b >= 10:
    print(-1)
else:
    print(a*b)

Solution (Python):
a, b = map(int, input().split())
if a<=9 and b<=9:
    print(a*b)
else:
    print("-1")

Solution (Python):
A, B = map(int, input().split())
print(A*B if 1 <= A <= 9 and 1 <= B <= 9 else "-1")

Solution (Python):
a,b=map(int,input().split())
if a<10 and b<10:
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b = map(int, input().split())
if a >= 10 or b>=10:
    print(-1)
else:
    print(a*b)

Solution (Python):
def q1():
    A,B = (int(i) for i in input().split())
    if A > 9 or B > 9:
        print(-1)
    else:
        print(A*B)


if __name__ == '__main__':
    q1()

Solution (Python):
a, b = map(int,input().split())

ans = -1
if a < 10 and b < 10:
    ans = a * b

print(ans)

Solution (Python):

a,b = map(int,input().split())
if a<10 and b<10:
    print(a*b)
else:
    print(-1)

Solution (Python):
a,b = map(int, input().split())
if a<10 and b<10: print(a*b)
else : print(-1)

Solution (Python):

A,B = (int(x) for x in input().split(" "))


if A<10 and B<10:
    print(A*B)
else:
    print(-1)

Solution (Python):
a, b = map(int, input().split())
if a > 9 or b > 9:
  print(-1)
else:
  print(a*b)

Solution (Python):
a, b = map(int, input().split())

if a<=9 and b<=9:
	print(a*b)
else:
	print(-1)

Solution (Python):
a,b = list(map(int,input().split()))
if 0<a<10 and 0<b<10:
    print(a*b)
else:
    print('-1')

Solution (Python):
A,B=map(int,input().split())

if (1<=A<=9)and(1<=B<=9):
  print(A*B)
else:
  print(-1)