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)
}

C++: #include <iostream>
#include <string>
#include <algorithm>
using namespace std;

static const int N = 1000;


int lcs(string X,string Y){
	
	int C[N+1][N+1];
int m = X.size();
int n = Y.size();
int max1 = 0;

X = ' '+X;
Y = ' '+Y;
for(int i=1;i<=m;i++) C[i][0] = 0;
for(int j=1;j<=n;j++) C[0][j] = 0;

for(int i=1;i<=m;i++){
	for(int j=1;j<=n;j++){
		if(X[i]==Y[j]){
			C[i][j] = C[i-1][j-1]+1; 
		}
		else {
			C[i][j] = max(C[i-1][j],C[i][j-1]);
		}
		max1 = max(max1,C[i][j]);
		}
	} 
	return max1;
}



int main(){
	int q;
	string s1,s2;
	cin>>q;
	for(int i=0;i<q;i++){
		cin>>s1>>s2;
		cout<<lcs(s1,s2)<<endl;
	}
	return 0;
}

C++: #include<bits/stdc++.h>

using namespace std;

int lcs(string X,string Y){
  //staticにしないと実行時にスタックオーバーフローになる
  static int c[1001][1001];
  int m = X.size();
  int n = Y.size();
  int maxl = 0;
  X = ' ' + X;
  Y = ' ' + Y;
  for(int i=0;i<=m;i++) c[i][0]=0;
  for(int j=1;j<=n;j++) c[0][j]=0;
  for(int i=1;i<=m;i++){
    for(int j=1;j<=n;j++){
      if(X[i]==Y[j]) c[i][j]=c[i-1][j-1]+1;
      else c[i][j]=max(c[i-1][j],c[i][j-1]);
      maxl=max(maxl,c[i][j]);
    }
  }
  return maxl;
}

int main(){
  int q;cin>>q;
  while(q--){
    string a,b;cin>>a>>b;
    cout << lcs(a,b) << endl;
  }
  return 0;
}

C++: #include<bits/stdc++.h>
#define ll long long int
#define FOR(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n)
using namespace std;

static const int N = 1000;

int Lcs(string X, string Y) {
  int c[N + 1][N + 1];
  int m = X.size();
  int n = Y.size();
  int maxl = 0;
  X = ' ' + X;
  Y = ' ' + Y;
  REP(i, m + 1) c[i][0] = 0;
  REP(i, n + 1) c[0][j] = 0;

  REP1(i, m + 1) {
    REP1(j, n + 1) {
      if ( X[i] == Y[j] ) {
        c[i][j] = c[i - 1][j - 1] + 1;
      } else {
        c[i][j] = max(c[i - 1][j], c[i][j - 1]);
      }
      maxl = max(maxl, c[i][j]);
    }
  }

  return maxl;
}

int main() {
  string s1, s2;
  int n;
  cin >> n;
  REP(i, n) {
    cin >> s1 >> s2;
    cout << Lcs(s1, s2) << endl;
  }
  return 0;
}

C++: #include<iostream>
#include<string>
using namespace std;

int dp[1005][1005];

int lcs(string x, string y){
    for (int i = 1; i <= x.size(); i++){
        for (int j = 1; j <= y.size(); j++)
        {
            if(x[i-1] != y[j-1])
                dp[i][j] = dp[i-1][j] > dp[i][j-1] ? dp[i-1][j] : dp[i][j-1];
            else
                dp[i][j] = dp[i-1][j-1] + 1;
        }
    }
    return dp[x.size()][y.size()];
}

int main()
{
    int n; cin >>n;
    string x, y;
    
    for (int i = 0; i < n; i++)
    {
        cin >> x >> y;
        cout << lcs(x, y) << endl;
    }
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main(void){
  int q;
  cin >> q;

  for(int i = 0; i < q; i++){
    string a, b;
    cin >> a;
    cin >> b;

    vector<vector<int> > dp(a.size() + 1, vector<int>(b.size() + 1, 0));
    for(int i = 0; i < (int)a.size(); i++){ dp[i][0] = 0; }
    for(int i = 0; i < (int)b.size(); i++){ dp[0][i] = 0; }

    for(int i = 1; i <= (int)a.size(); i++){
      for(int j = 1; j <= (int)b.size(); j++){
        dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);
        if(a[i - 1] == b[j - 1])
          dp[i][j] = max(dp[i][j], dp[i - 1][j - 1] + 1);
      }
    }

    cout << dp[a.size()][b.size()] << endl;
  }
  
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> P;
constexpr int di[] = { 0, 1, 0, -1 }, dj[] = { 1, 0, -1, 0 };
#define rep(i, n) for (int i = 0; i < n; i++)
#define repr(i, n) for (int i = n; i >= 0; i--)
#define SORT(v) sort((v).begin(), (v).end())
#define SORTR(v) sort((v).rbegin(), (v).rend())
#define all(v) (v).begin(), (v).end()
#define vmax 10000
constexpr ll inf = 100000000000000;
/*cout<<fixed<<setprecision(20);cin.tie(0);ios::sync_with_stdio(false);*/

static const int N=1000;

int lcs(string x,string y){
  int c[N+1][N+1];
  int m=x.size();
  int n=y.size();
  int maxl=0;
  x=' '+x;//x[0]に空白を挿入
  y=' '+y;//y[0]に空白を挿入
  for(int i=0;i<=m;i++) c[i][0]=0;
  for(int i=1;i<=n;i++) c[0][i]=0;

  for(int i=1;i<=m;i++){
    for(int j=1;j<=n;j++){
      if(x[i]==y[j]){
        c[i][j]=c[i-1][j-1]+1;
      }else{
        c[i][j]=max(c[i-1][j],c[i][j-1]);
      }
      maxl=max(maxl,c[i][j]);
    }
  }

  return maxl;
}

int main(){
  string s1,s2;
  int n;cin>>n;
  rep(i,n){
    cin>>s1>>s2;
    cout<<lcs(s1,s2)<<endl;
  }
  return 0;
}

C++: #include <iostream>
#include <cstring>

using namespace std;

int main(void)
{
    int q;
    char x[1001], y[1001];
    int table[1001][1001];
    
    cin >> q;
    for (int i = 0; i < q; i++) {
	cin >> x >> y;
	int xl = strlen(x), yl = strlen(y);

	for (int i = 0; i < xl; i++)
	    for (int j = 0; j < yl; j++)
		if (x[i] == y[j])
		    table[i+1][j+1] = 1 + table[i][j];
		else
		    table[i+1][j+1] = max(table[i][j+1], table[i+1][j]);

	cout << table[xl][yl] << endl;
    }

    return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<string>
using namespace std;

int Longest(string x, string y) {
  int L[1001][1001];
  int maxl = -1;
  int xlen = x.size();
  int ylen = y.size();

  x = ' ' + x;
  y = ' ' + y;

  for (int i = 1; i <= xlen; i++) L[i][0] = 0;
  for (int j = 1; j <= ylen; j++) L[0][j] = 0;

  for (int i = 1; i <= xlen; i++) {
    for (int j = 1; j <= ylen; j++) {
      if (x[i] == y[j])
        L[i][j] = L[i-1][j-1] + 1;
      else
        L[i][j] = max(L[i][j-1], L[i-1][j]);

      maxl = max(maxl, L[i][j]);
    }
  }

  return maxl;
}

int main() {
  string X, Y;
  int n;
  int result[1001];

  cin >> n;

  for (int i = 0; i < n; i++) {
    cin >> X;
    cin >> Y;
    result[i] =  Longest(X, Y);
    cout << result[i] << endl;
  }

  


  return 0;
}