# read OV-input
# read set size and vector dimension
n, d = map(int, input().split()) 
# read vectors
U = n * [None]
for i in range(n):
    U[i] = input()
    
V = n * [None]
for i in range(n):
    V[i] = input()

# each U[i] and V[i] contains a string of length d
# the string characters are 0/1
# each string represents a d-dimensional vector from {0,1}^d

################################
# TODO - start
# Construct regular expression and string.
# Your construction should take O(nd) time.

regexp = ".*"
string = "hello world"

## TODO - end
################################

local_test = False # set to True if you test locally

if local_test:
    # if test locally, the true/false output should match the 0/1 in the test case output file
    import re
    print(re.match(regexp, string))
else:
    # print regexp and string
    # autograder will call re.match(regexp, string)
    print(regexp)
    print(string)