result = []
for _ in range(int(input())) :
    a, b = map(int, input().split())
    a %= 10
    
    if a==0 : result.append("10")
    elif a in [1, 5, 6] : result.append(str(a))
    elif a in [4, 9] : result.append(str(a) if b%2 else str(a*a%10))
    else : result.append(str(a**(b%4)%10) if b%4 else str(a**4%10))
    
print('\n'.join(result))