Go: package main

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

//Util
func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func maxInt(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func minInt(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

func absInt(a int) int {
	if a >= 0 {
		return a
	} else {
		return -a
	}
}

func absFloat64(a float64) float64 {
	if a >= 0 {
		return a
	} else {
		return -a
	}
}

func minFloat64(a, b float64) float64 {
	if a > b {
		return b
	} else {
		return a
	}
}

func str2Int(s string) int {
	n, _ := strconv.Atoi(s)
	return n
}

//Main
var sc = bufio.NewScanner(os.Stdin)
var q int
var X, Y string

func lcs(X, Y string) int {
	lenX := len(X)
	lenY := len(Y)
	dp := make([][]int, lenX+1)
	for i := 0; i < lenX+1; i++ {
		dp[i] = make([]int, lenY+1)
	}

	res := 0
	for i := 1; i < lenX+1; i++ {
		for j := 1; j < lenY+1; j++ {
			if X[i-1] == Y[j-1] {
				dp[i][j] = dp[i-1][j-1] + 1
			} else {
				dp[i][j] = maxInt(dp[i-1][j], dp[i][j-1])
			}
			//fmt.Println(dp)
			res = maxInt(res, dp[i][j])
		}

	}
	return res
}

func main() {
	sc.Split(bufio.ScanWords)
	q = nextInt()

	for i := 0; i < q; i++ {
		X = nextStr()
		Y = nextStr()

		fmt.Println(lcs(X, Y))
	}
}

Python: q=int(input())
for i in range(q):
    s1=input()
    s2=input()
    ls1=len(s1)
    ls2=len(s2)
    f=[[0 for k in range(ls2+1)] for j in range(ls1+1)]
    f[0][0]=0
    for l in range(ls1+1):
        f[l][0]=0
    for l in range(ls2+1):
        f[0][l]=0
    for j in range(1,ls1+1):
        for k in range(1,ls2+1):
            if s1[j-1]==s2[k-1]:
                f[j][k]=f[j-1][k-1]+1
            else:
                f[j][k]=max(f[j-1][k],f[j][k-1])
    print(f[j][k])

Python: N = int(input())

for _ in range(N):
    x = input()
    y = input()
    m, n = len(x), len(y)
    dp = [0] * (n+1)
    
    for xi in x:
        temp = dp[:]
        for j in range(n):
            if xi == y[j]:
                dp[j+1] = temp[j] + 1
            elif dp[j+1] < dp[j]:
                dp[j+1] = dp[j]
                
    print(dp[-1])

Python: # -*- coding: utf-8 -*-
import functools


def lcs(x, y):
    n = len(x)
    m = len(y)
    return rec(x, y, n, m)


@functools.lru_cache(maxsize=None)
def rec(x, y, i, j):
    if i == 0 or j == 0:
        return 0
    elif x[i - 1] == y[j - 1]:
        return rec(x, y, i - 1, j - 1) + 1
    else:
        return max(rec(x, y, i, j - 1), rec(x, y, i - 1, j))


if __name__ == '__main__':
    import sys
    q = int(sys.stdin.readline().strip())
    for i in range(q):
        x = sys.stdin.readline().strip()
        y = sys.stdin.readline().strip()
        print(lcs(x, y))

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
input:
3
abcbdab
bdcaba
abc
abc
abc
bc

output:
4
3
2

"""
import sys


def lcs(A, B):
    m, n = len(A), len(B)
    count_list = [[0] * (n + 1) for _ in range(m + 1)]

    for i in range(1, m + 1):
        for j in range(1, n + 1):
            if A[i - 1] == B[j - 1]:
                count_list[i][j] = count_list[i - 1][j - 1] + 1
            elif count_list[i - 1][j] >= count_list[i][j - 1]:
                count_list[i][j] = count_list[i - 1][j]
            else:
                count_list[i][j] = count_list[i][j - 1]

    return count_list[m][n]


def lcs_better(X, Y):
    costs = [0]
    for c in Y:
        for i in range(len(costs) - 1, -1, -1):
            tmp = X.find(c, costs[i])
            if tmp + 1:
                if i + 1 < len(costs):
                    costs[i + 1] = min(costs[i + 1], tmp + 1)
                else:
                    costs.append(tmp + 1)
    return len(costs) - 1


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    pair_num = int(_input[0])

    word_list = _input[1:]
    # assert len(word_list) == 2 * pair_num
    for k in range(0, len(word_list), 2):
        print(lcs_better(word_list[k].strip(), word_list[k + 1].strip()))

Python: def lcs(s, t):
  slen = len(s)
  tlen = len(t)
  dp = [0] * (slen + 1)
  for i in range(slen + 1):
    dp[i] = [0] * (tlen + 1)

  for i in range(1, slen + 1):
    for j in range(1, tlen + 1):
      if s[i-1] == t[j-1]:
        dp[i][j] = dp[i-1][j-1] + 1
      else:
        dp[i][j] = max(dp[i][j-1], dp[i-1][j])

  return dp[slen][tlen]

n = int(raw_input())

for i in range(n):
  x = raw_input()
  y = raw_input()
  print(lcs(x, y))

Python: Q = int(input().strip())
for q in range(Q):
    X = str(input().strip())
    Y = str(input().strip())
    lx = len(X)
    ly = len(Y)
    L = [[0 for j in range(0,ly+1)] for i in range(0,lx+1)]
    for i in range(1,lx+1):
        for j in range(1,ly+1):
            if X[i-1] == Y[j-1]:
                L[i][j] = 1 + L[i-1][j-1]
            else:
                L[i][j] = max(L[i-1][j],L[i][j-1])
    print(L[lx][ly])

Python: # -*- coding: utf-8 -*-
def lcs(x, y):
    dp = {(0, 0): 0}
    for i in range(1, len(x) + 1):
        dp[(i, 0)] = 0
    for j in range(1, len(y) + 1):
        dp[(0, j)] = 0
    for i in range(1, len(x) + 1):
        for j in range(1, len(y) + 1):
            if x[i - 1] == y[j - 1]:
                dp[(i, j)] = dp[(i - 1, j - 1)] + 1
            else:
                dp[(i, j)] = max(dp[(i - 1, j)], dp[(i, j - 1)])

    return dp[(len(x), len(y))]


def lcs_sol(x, y):
    n = len(x)
    m = len(y)
    dp = [[0 for j in range(m + 1)] for i in range(n + 1)]

    for i in range(1, n + 1):
        for j in range(1, m + 1):
            if x[i - 1] == y[j - 1]:
                dp[i][j] = dp[i - 1][j - 1] + 1
            else:
                dp[i][j] = max(dp[i - 1][j], dp[i][j - 1])

    return dp[n][m]

if __name__ == '__main__':
    import sys
    q = int(sys.stdin.readline().strip())
    for i in range(q):
        x = sys.stdin.readline().strip()
        y = sys.stdin.readline().strip()
        print(lcs_sol(x, y))

Python: q = int(input())
for _ in range(q):
    x = input()
    y = input()
    n = len(x)
    m = len(y)
    dp = [0 for j in range(m + 1)]

    for i in range(1, n + 1):
        dp_prev = dp[:]
        for j in range(1, m + 1):
            if x[i - 1] == y[j - 1]:
                dp[j] = dp_prev[j - 1] + 1
            elif dp_prev[j] < dp[j - 1]:
                dp[j] = dp[j - 1]
            else:
                dp[j] = dp_prev[j]

    print(dp[m])

Python: def gen_dp(row, col):
  return [[0]*col for i in range(row)]

def solver(str_1 ,str_2):
  dp = gen_dp(len(str_2) + 1, len(str_1) + 1)
  for r in range(len(str_2)):
    for c in range(len(str_1)):
      if str_2[r] == str_1[c]:
        dp[r + 1][c + 1] = dp[r][c] + 1
      else:
        dp[r + 1][c + 1] = max(dp[r + 1][c], dp[r][c + 1])
  return dp[len(str_2)][len(str_1)]

n = int(input())
for _ in range(n):
  str_1 = input()
  str_2 = input()
  print(solver(str_1, str_2))

Python: def ask(X,Y):
 cost=[0]
 for j in Y:
  for i in range(len(cost)-1,-1,-1):
   a=X.find(c,cost[i])+1
   if a:
    if i+1<len(cost):
     cost[i+1]=min(cost[i+1],a)
    else:
     cost.append(a)
 return len(cost)-1
 


q=int(input())
Z=[]
for p in range(q):
 X=input()
 Y=input()
 z=ask(X,Y)
 Z.append(z)

for p in range(q):
 print(Z[p])

Python: # -*- coding:utf-8 -*-
import sys
 
 
def search(x, y):
    x_length = len(x)
    y_length = len(y)
    memo = [[0] * (y_length + 1) for i in range(x_length + 1)]
    for i, ch_x in enumerate(x, 1):
        row = memo[i]
        pre_row = memo[i-1]
        for j, ch_y in enumerate(y, 1):
            if ch_x == ch_y:
                row[j] = pre_row[j-1] + 1
            elif pre_row[j] < row[j-1]:
                row[j] = row[j-1]
            else:
                row[j] = pre_row[j]
    return memo[-1][-1]
 
 
if __name__ == "__main__":
    n = int(input())
    strs = [list(val) for val in sys.stdin.read().splitlines()]
    result = [search(strs[i*2], strs[i*2+1]) for i in range(n)]
    print(*result, sep="\n")