"""

# 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

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

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

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

match = 1 if x[i - 1] == y[j - 1] else 0

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

seq = ""

i, j = m, n

while i > 0 and j > 0:

match = 1 if x[i - 1] == y[j - 1] else 0

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

if match == 1:

seq = x[i - 1] + seq

i -= 1

j -= 1

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

i -= 1

else:

j -= 1