# include <stdio.h>

 # include <stdlib.h>

 typedef struct node

 {

     int num;

     struct node *q;

     struct node *h;

 }node;

 struct Node

 {

     node *start;

     node *end;

     int sum;

 }m[];

 int main()

 {

     int k;

     scanf("%d", &k);

     while (k--)

     {

         int n, p;

         scanf("%d%d", &n, &p);

         for (int i = ; i <= n; i++)

         {

             m[i].end = NULL;

             m[i].start = NULL;

             m[i].sum = ;

         }

         for (int i = ; i<p; i++)

         {

             int op, s, v, t;

             scanf("%d", &op);

             if (op == )

             {

                 scanf("%d%d", &s, &v);

                 if (m[s].sum == )

                 {

                     m[s].start = (node *)malloc(sizeof(node));

                     m[s].start->num = v;

                     m[s].start->q = NULL;

                     m[s].start->h = NULL;

                     m[s].end = NULL;

                     m[s].sum = ;

                 }

                 else

                 if (m[s].sum == )

                 {

                     m[s].end = (node *)malloc(sizeof(node));

                     m[s].end->num = v;

                     m[s].end->q = m[s].start;

                     m[s].end->h = NULL;

                     m[s].start->h = m[s].end;

                     m[s].sum = ;

                 }

                 else

                 {

                     node * z = (node *)malloc(sizeof(node));

                     z->num = v;

                     z->q = m[s].end;

                     z->h = NULL;

                     m[s].end->h = z;

                     m[s].end = z;

                     m[s].sum++;

                 }

             }

             else

             if (op == )

             {

                 scanf("%d", &s);

                 if (m[s].sum == )

                     printf("EMPTY\n");

                 else

                 {

                     m[s].sum--;

                     if (m[s].sum != )

                         printf("%d\n", m[s].end->num);

                     else

                         printf("%d\n", m[s].start->num);

                     if (m[s].sum != )

                     {

                         node *z = m[s].end->q;

                         z->h = NULL;

                         m[s].end = z;

                     }

                     else

                     {

                         m[s].end = NULL;

                         m[s].start = NULL;

                     }

                 }

             }

             else

             {

                 scanf("%d%d", &s, &t);

                 if (m[s].sum == )

                 {

                     m[s].end = m[t].end;

                     m[s].start = m[t].start;

                     m[s].sum = m[t].sum;

                     m[t].sum = ;

                     m[t].end = NULL;

                     m[t].start = NULL;

                 }

                 else

                 if (m[s].sum == )

                 {

                     m[s].sum += m[t].sum;

                     m[t].sum = ;

                     if (m[t].start != NULL)

                     {

                         m[s].end = m[t].start;

                         m[s].start->h = m[t].start;

                         m[s].end->q = m[s].start;

                         if (m[t].end != NULL)

                             m[s].end = m[t].end;

                         else

                             m[s].end = m[t].start;

                     }

                     m[t].start = NULL;

                     m[t].end = NULL;

                 }

                 else

                 {

                     m[s].sum += m[t].sum;

                     m[t].sum = ;

                     if (m[t].start != NULL)

                     {

                         m[s].end->h = m[t].start;

                         m[t].start->q = m[s].end;

                         if (m[t].end != NULL)

                             m[s].end = m[t].end;

                         else

                             m[s].end = m[t].start;

                     }

                     m[t].start = NULL;

                     m[t].end = NULL;

                 }

             }

         }

     }

     //system("pause");

     return ;

 }