Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	Q := sc.nextInt()
	for q := 0; q < Q; q++ {
		X, Y := sc.nextStr(), sc.nextStr()
		xLen, yLen := len(X), len(Y)
		dp := make([][]int, xLen+1)
		for i := 0; i <= xLen; i++ {
			dp[i] = make([]int, yLen+1)
		}
		for x := 0; x <= xLen; x++ {
			for y := 0; y <= yLen; y++ {
				if x == 0 || y == 0 {
					dp[x][y] = 0
				} else if X[x-1] == Y[y-1] {
					dp[x][y] = dp[x-1][y-1] + 1
				} else {
					dp[x][y] = max(dp[x-1][y], dp[x][y-1])
				}
			}
		}
		fmt.Fprintln(wtr, dp[xLen][yLen])
	}

	wtr.Flush()
}

Python: n = int(input())
import sys

def input():
    return sys.stdin.readline().rstrip()
ans = []
def calc(s1,s2):
    lens1 = len(s1)
    lens2 = len(s2)
    # print(len(s1),s1[-1])
    dp = [0]*(lens2+1)
    for i in range(lens1):
        dp2 = dp[:]
        e = s1[i]
        for j in range(lens2):
            if e == s2[j]:
                dp[j+1] = dp2[j] + 1
            elif dp[j]>dp[j+1]:
                dp[j+1] = dp[j]
    # print(dp)
    ans.append(dp[-1])


for i in range(n):
    s1 = input()
    s2 = input()
    calc(s1,s2)
for i in ans:
    print(i)

# def lcs(x, y):
#     a = len(x)
#     b = len(y)
#     c1 = [0] * (b + 1)
#     for i in range(a):
#         e1 = x[i]
#         c2 = c1[:]
#         for j in range(b):
#             if e1 == y[j]:
#                 c1[j+1] = c2[j] + 1
#             elif c1[j+1] < c1[j]:
#                 c1[j+1] = c1[j]
#     return c1[-1]
    
# n = int(input().rstrip())
# ret = []
# for i in range(n):
#     s1 = input().rstrip()
#     s2 = input().rstrip()
#     ret.append(lcs(s1, s2))
# print(*ret, sep="\n")

Python: # -*- coding: utf-8 -*-
import sys
from itertools import product
sys.setrecursionlimit(100000)

N = int(input())

def calc_LCS(n, m):
    if n == 0 or m == 0:
        return 0
    elif X[n] == Y[m]:
        LCS[n][m] = LCS[n-1][m-1] + 1
        return LCS[n][m]
    else:
        LCS[n][m] = max(LCS[n-1][m], LCS[n][m-1])
        return LCS[n][m]
        

for _ in range(N):
    X = ["  "] + list(input())
    Y = [" "] + list(input())
    LCS = [[0 for _ in range(len(Y))] for _ in range(len(X))]
    max_ = 0
    for n, m in product(range(len(X)), range(len(Y))):
        max_ = max(max_, calc_LCS(n, m))
    print(max_)

Python: from collections import defaultdict


def longest_common_subsequence(s, t):
    dp = [[0] * (len(t) + 1) for _ in range(len(s) + 1)]
    for i in range(len(s)):
        for j in range(len(t)):
            if s[i] == t[j]:
                dp[i + 1][j + 1] = dp[i][j] + 1
            else:
                dp[i + 1][j + 1] = max(dp[i + 1][j], dp[i][j + 1])
    return dp[-1][-1]


def longest_common_subsequence2(s, t):
    dp = [0] * (len(t) + 1)
    for i in range(len(s)):
        si = s[i]
        tmp = dp[:]
        for j in range(len(t)):
            if si == t[j]:
                dp[j + 1] = tmp[j] + 1
            elif dp[j + 1] < dp[j]:
                dp[j + 1] = dp[j]
    return dp[-1]


def main():
    n = int(input())
    for _ in range(n):
        X, Y = input(), input()
        print(longest_common_subsequence2(X, Y))


if __name__ == '__main__':
    main()

Python: def lcs(str1,str2):
    c=[[0 for _ in range(100000)] for _ in range(100000)]
    m=len(str1)
    n=len(str2)
    maxl=0
    str1=" "+str1
    str2=" "+str2

    i=1
    j=1
    while(i<=m):
        while(j<=n):
            if(str1[i]==str2[j]):
                c[i][j]=c[i-1][j-1]+1
              #  print(c[i][j])
            else:
                c[i][j]=max(c[i-1][j],c[i][j-1])
            maxl=max(maxl,c[i][j])
            j+=1
        i+=1
        j=0

    return maxl

def main():
    n=int(input())
    i=0
    while(i<n):
        str1=str(input())
        str2=str(input())
        print(int(lcs(str1,str2)))
        i+=1

main()

Python: def lcs(x, y):
    a = len(x)
    b = len(y)
    c1 = [0] * (b + 1)
    for i in range(a):
        c2 = c1[:]
        for j in range(b):
            if x[i] == y[j]:
                c1[j+1] = c2[j] + 1
            elif c1[j+1] < c1[j]:
                c1[j+1] = c1[j]
    return c1[-1]
   
n = int(input().rstrip())
ret = [0] * n
for i in range(n):
    s1 = input().rstrip()
    s2 = input().rstrip()
    ret[i] = lcs(s1, s2)
for i in range(n):
    print(ret[i])

Python: q = int(input())
for i in range(q):
    x = input()
    y = input()
    co = []

    for j, s in enumerate(x):
        co.append([])
        co[j].append(-1)
        if j == 0:
            end = y.find(s)
            if end != -1:
                co[j].append(end)
        else:
            for k, t in enumerate(co[j-1][:-1]):
                end = y.find(s, t+1)
                if end != -1:
                    co[j].append(min(end, co[j-1][k+1]))
                else:
                    co[j].append(co[j-1][k+1])
            end = y.find(s, co[j-1][-1]+1)

            if end != -1:
                co[j].append(end)

    print(len(co[-1])-1)