"""

# find the length of strings

assert x is not None

assert y is not None

m = len(x)

n = len(y)

# declaring the array for storing the dp values

L = [[0] * (n + 1) for _ in range(m + 1)]

for i in range(1, m + 1):

for j in range(1, n + 1):

if x[i - 1] == y[j - 1]:

match = 1

else:

match = 0

L[i][j] = max(L[i - 1][j], L[i][j - 1], L[i - 1][j - 1] + match)

seq = ""

i, j = m, n

while i > 0 and j > 0:

if x[i - 1] == y[j - 1]:

match = 1

else:

match = 0

if L[i][j] == L[i - 1][j - 1] + match:

if match == 1:

seq = x[i - 1] + seq

i -= 1

j -= 1

elif L[i][j] == L[i - 1][j]:

i -= 1

else:

j -= 1