Buggy python submission (verdict: Time Limit Exceeded):
import sys
input=sys.stdin.readline
s=' '+input().rstrip()
t=' '+input().rstrip()
dp=[['']*len(t) for i in range(len(s))]
for i in range(1,len(s)):
    for j in range(1,len(t)):
        if s[i]==t[j]:
            dp[i][j]=dp[i-1][j-1]+s[i]
        else:
            if len(dp[i-1][j])>len(dp[i][j-1]):
                dp[i][j]=dp[i-1][j]
            else:
                dp[i][j]=dp[i][j-1]
print(dp[len(s)-1][len(t)-1])








Fixed submission:
import sys
input=sys.stdin.readline
s=' '+input().rstrip()
t=' '+input().rstrip()
m=len(s)-1
n=len(t)-1
dp=[[0]*(n+1) for i in range(m+1)]
for i in range(1,m+1):
    for j in range(1,n+1):
        if s[i]==t[j]:
            dp[i][j]=dp[i-1][j-1]+1
        else:
            dp[i][j]=max(dp[i-1][j],dp[i][j-1])
ans=''
while m>0 and n>0:
    if dp[m][n]==dp[m][n-1]:
        n-=1
    elif dp[m][n]==dp[m-1][n]:
        m-=1
    elif dp[m][n]==dp[m-1][n-1]+1:
        ans=s[m]+ans
        m-=1
        n-=1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
s=' '+input()
t=' '+input()
dp=[]
dp_l=[]
for i in range(len(s)):
    sub_list=[]
    l_list=[]
    for j in range(len(t)):
        sub_list.append('')
        l_list.append(0)
    dp.append(sub_list)
    dp_l.append(l_list)
for i in range(1,len(s)):
    for j in range(1,len(t)):
        if s[i]==t[j]:
            dp[i][j]=dp[i-1][j-1]+s[i]
            dp_l[i][j]=dp_l[i-1][j-1]+1
        else:
            if dp_l[i-1][j]>dp_l[i][j-1]:
                dp[i][j]=dp[i-1][j]
                dp_l[i][j]=dp_l[i-1][j]
            else:
                dp[i][j]=dp[i][j-1]
                dp_l[i][j]=dp_l[i][j-1]
print(dp[len(s)-1][len(t)-1])


Fixed submission:
import sys
input=sys.stdin.readline
s=' '+input().rstrip()
t=' '+input().rstrip()
m=len(s)-1
n=len(t)-1
dp=[[0]*(n+1) for i in range(m+1)]
for i in range(1,m+1):
    for j in range(1,n+1):
        if s[i]==t[j]:
            dp[i][j]=dp[i-1][j-1]+1
        else:
            dp[i][j]=max(dp[i-1][j],dp[i][j-1])
ans=''
while m>0 and n>0:
    if dp[m][n]==dp[m][n-1]:
        n-=1
    elif dp[m][n]==dp[m-1][n]:
        m-=1
    elif dp[m][n]==dp[m-1][n-1]+1:
        ans=s[m]+ans
        m-=1
        n-=1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
s=' '+input()
t=' '+input()
dp=[]
for i in range(len(s)):
    sub_list=[]
    for j in range(len(t)):
        sub_list.append('')
    dp.append(sub_list)
for i in range(1,len(s)):
    for j in range(1,len(t)):
        if s[i]==t[j]:
            dp[i][j]=dp[i-1][j-1]+s[i]
        else:
            if len(dp[i-1][j])>len(dp[i][j-1]):
                dp[i][j]=dp[i-1][j]
            else:
                dp[i][j]=dp[i][j-1]
print(dp[len(s)-1][len(t)-1])


Fixed submission:
import sys
input=sys.stdin.readline
s=' '+input().rstrip()
t=' '+input().rstrip()
m=len(s)-1
n=len(t)-1
dp=[[0]*(n+1) for i in range(m+1)]
for i in range(1,m+1):
    for j in range(1,n+1):
        if s[i]==t[j]:
            dp[i][j]=dp[i-1][j-1]+1
        else:
            dp[i][j]=max(dp[i-1][j],dp[i][j-1])
ans=''
while m>0 and n>0:
    if dp[m][n]==dp[m][n-1]:
        n-=1
    elif dp[m][n]==dp[m-1][n]:
        m-=1
    elif dp[m][n]==dp[m-1][n-1]+1:
        ans=s[m]+ans
        m-=1
        n-=1
print(ans)