Problem:
Score : 100 points

Problem Statement

You are given strings s and t.
Find one longest string that is a subsequence of both s and t.

Notes

A subsequence of a string x is the string obtained by removing zero or more characters from x and concatenating the remaining characters without changing the order.

Constraints

s and t are strings consisting of lowercase English letters.

1 \leq |s|, |t| \leq 3000

Input

Input is given from Standard Input in the following format:

s
t

Output

Print one longest string that is a subsequence of both s and t.
If there are multiple such strings, any of them will be accepted.

Sample Input 1

axyb
abyxb

Sample Output 1

axb

The answer is axb or ayb; either will be accepted.

Sample Input 2

aa
xayaz

Sample Output 2

aa

Sample Input 3

a
z

Sample Output 3

The answer is (an empty string).

Sample Input 4

abracadabra
avadakedavra

Sample Output 4

aaadara

Solution in PyPy3 (2.4.0) (judge verdict: Accepted)

s=input()
t=input()
n=len(s)
m=len(t)
dp=[[0 for x in range(n+1)] for y in range(m+1)]
for i in range(1,m+1):
    for j in range(1,n+1):
        if(s[j-1]==t[i-1]):
            dp[i][j]=1+dp[i-1][j-1]
        else:
            temp=max(dp[i-1][j],dp[i][j-1])
            dp[i][j]=temp
i,j=m,n
ans=''
while (i>0 and j>0):
    if(s[j-1]==t[i-1]):
        ans+=s[j-1]
        i-=1
        j-=1
    else:
        if(dp[i-1][j]>dp[i][j-1]):
            i-=1
        else:
            j-=1
print(ans[::-1])