#include<iostream>
    #include<sstream>
    #include<string>
    #include<cstdlib>
    #include<vector>
    #include<map>
    #include<queue>
    #include<stack>
    #include<cmath>
    #include<cctype>
    #include<set>
    #include<bitset>
    #include<algorithm>
    #include<list>

    #include<stdio.h>
    #include<string.h>
    #include<stdlib.h>
    #include<math.h>
    #include<ctype.h>
    using namespace std;
    typedef long long int ll;
    #define PI           3.14159265358979323846
    struct node{
        int x,y;
    }res[110][110];
  string s1,s2,ss1,ss2;
  bool vis[110][110];
  string ans;
  int dp[110][110],mm[110][110];
  void cal(int i,int j)
  {
     if(dp[i][j]==0)
     return ;
     if(vis[i][j]==1)
     {

             ans+=s1[i];
          cout<<ans<<endl;
     }

     cal(res[i][j].x,res[i][j].y);

  }
    int main()
    {
           //freopen("0in.txt","r",stdin);
           //freopen("0out.txt","w",stdout);
          int tcase,t,i,j,cnt,end,l1,l2;

          scanf("%d",&tcase);
          for(t=1;t<=tcase;t++)
          {
              cin>>ss1>>ss2;
              s1="";
              s2="";

              char ch='z'+1;
              s1 = "#"+ss1;
              s2 = "#"+ss2;
              l1 = ss1.size();
              l2 = ss2.size();
              memset(dp,0,sizeof dp);
              for(i=0;i<=l1;i++)
              mm[i][0]='z'+1;
              for(i=0;i<=l2;i++)
              mm[0][i]='z'+1;
              for(i=1;i<=l1;i++)
              {
                for(j=1;j<=l2;j++)
                {
                    vis[i][j] = 0;
                    res[i][j].x=0;
                    res[i][j].y = 0;
                   if(s1[i]==s2[j])
                    {
                            dp[i][j] = dp[i-1][j-1] + 1;

                    }
                    else
                    {
                            dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
                    }
                }
             }
             for(i=0;i<=l2;i++)
             cout<<s2[i]<<" ";
             cout<<endl;

             for(i=1;i<=l1;i++)
             {
                cout<<s1[i]<<" ";
                 for(j=1;j<=l2;j++)
                 {
                    if(s1[i]==s2[j])
                     {
                        res[i][j].x = i-1;
                        res[i][j].y = j-1;
                        vis[i][j] = 1;
                        mm[i][j]=s1[i]-96;
                        cout<<"A"<<" ";
                     }
                     else if(dp[i-1][j]==dp[i][j-1])
                     {
                         if(mm[i][j-1]<mm[i-1][j])
                         {
                            res[i][j].x = i;
                            res[i][j].y = j-1;
                            mm[i][j]=mm[i][j-1];
                            cout<<"L"<<" ";
                         }
                         else
                         {
                             res[i][j].x = i-1;
                             res[i][j].y = j;
                             mm[i][j]=mm[i-1][j];
                             cout<<"U"<<" ";
                         }
                     }
                     else
                     {
                         if(dp[i-1][j]>dp[i][j-1])
                         {
                            res[i][j].x = i-1;
                            res[i][j].y = j;
                            mm[i][j]=mm[i-1][j];
                            cout<<"U"<<" ";
                          }
                          else{

                             res[i][j].x = i;
                            res[i][j].y = j-1;
                            mm[i][j]=mm[i][j-1];
                            cout<<"L"<<" ";
                        }
                     }
                 }
                 cout<<endl<<endl;
             }


             ans = "";
             //cal(l1,l2);
             i=l1;
             j=l2;

             while(dp[i][j]!=0)
             {

     if(vis[i][j]==1)
     {

             ans=s1[i]+ans;

     }
     i=res[i][j].x;j=res[i][j].y;
             }
             cout<<ans<<endl;


          }


    return 0;
    }