Go: package main

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

var (
	nstr   func() string
	stdout *bufio.Writer
)

func init() {
	nstr = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func main() {
	defer stdout.Flush()

	n := nint()
	xList := make([]string, n)
	yList := make([]string, n)

	for i:=0;i<n ;i++  {
		xList[i] = nstr()
		yList[i] = nstr()
	}

	for i := 0; i<n	; i++  {
		fmt.Println(lcs(xList[i], yList[i]))
	}

}

func lcs(x string, y string) int{
	var m = len(x)
	var n = len(y)

	c := make([][]int, m+1)
	for i:= range c{
		c[i] = make([]int, n+1)
	}
	for i:=	1;i<=m ;i++  {
		for j:=1;j<=n ;j++  {
			if x[i-1] == y[j-1]{
				c[i][j] = c[i-1][j-1] + 1
			}else{
				c[i][j] = int(math.Max(float64(c[i-1][j]), float64(c[i][j-1])))
			}


		}
	}
	return c[m][n]

}


func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+11))
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

func nint64() int64 {
	i, err := strconv.ParseInt(nstr(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func nint() int {
	return int(nint64())
}

func getIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = nint()
	}
	return b
}

func getStringSlice(n int) []string {
	b := make([]string, n)
	for i := 0; i < n; i++ {
		b[i] = nstr()
	}
	return b
}

func gcd(x, y int) int {
	if y == 0 {
		return x
	}
	return gcd(y, x%y)
}

func lcm(x, y int) int {
	return x * y / gcd(x, y)
}

func contains(s []int, e int) bool {
	for _, a := range s {
		if a == e {
			return true
		}
	}
	return false
}

func bin(i int, prefix bool) string {
	i64 := int64(i)

	if prefix {
		return "0b" + strconv.FormatInt(i64, 2)
	} else {
		return strconv.FormatInt(i64, 2)
	}
}

func strReverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}

	return string(runes)
}

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

output:
4
3
2

"""
import sys

sys.setrecursionlimit(int(1e5))


def lcs(w1, w2):
    m, n = len(w1), len(w2)
    dp = tuple([0] * (n + 1) for _ in range(m + 1))
    max_l = 0
    for i in range(1, m + 1):
        for j in range(1, n + 1):
            if w1[i - 1] == w2[j - 1]:
                dp[i][j] = dp[i - 1][j - 1] + 1
            else:
                dp[i][j] = max(dp[i - 1][j], dp[i][j - 1])
            max_l = max(max_l, dp[i][j])

    return max_l


def lcs_recursive(w1, w2, m, n):
    if m == 0 or n == 0:
        return 0
    elif w1[m - 1] == w2[n - 1]:
        return 1 + lcs_recursive(w1, w2, m - 1, n - 1)
    else:
        return max(lcs_recursive(w1, w2, m, n - 1), lcs_recursive(w1, w2, m - 1, n))


def solve():
    _input = sys.stdin.readlines()
    pair_num = int(_input[0])
    word_list = _input[1:]
    # assert len(word_list) == 2 * pair_num

    for pair in zip(word_list[::2], word_list[1::2]):
        cw1, cw2 = map(lambda x: x.strip(), pair)
        print(lcs(cw1, cw2))
        # l1, l2 = len(cw1), len(cw2)
        # print(lcs_recursive(cw1, cw2, l1, l2))

    return None


if __name__ == '__main__':
    solve()

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))