/* Sat Oct 25 02:01:23 JST 2003 */

#include <stdio.h>
#include <stdlib.h>

#define WIDTH 128

#define LEFTMOST(x,y) ((map[y][x].n>0)&&((x)==0||((x)>0&&map[y][x-1].n==0)))
#define TAIL(x,y) ((x)>0&&map[y][x].n==0&&map[y][x-1].n>0)
#define MOVABLETO(xx,yy) ((xx)>=0&&(yy)>=0&&((map[yy][xx].n>0)||(map[yy][xx-1].n>0)))

typedef struct _char_t {
  unsigned char c;
  int n;
} char_t;

char_t map[WIDTH][WIDTH];

void output(int _x, int _y)
{
  int x, y;
  printf("(%d,%d)\n", _x, _y);
  for (y = 5; y >= 0; y--) {
    for (x = 0; x < 10; x++) {
      if (x == _x && _y == y) {
	if (map[y][x].n == 0) printf("-[0] ");
	else printf("%c[%d] ", map[y][x].c, map[y][x].n);
      }
      else {
	if (map[y][x].n == 0) printf("-(0) ");
	else printf("%c(%d) ", map[y][x].c, map[y][x].n);
      }
    }
    printf("\n");
  }
}

int searchtail(int x, int y)
{
  int i, target;

  target = map[y][x].n;
  for (i = x; i < WIDTH; i++) {
    if (map[y][i].n != target) return i;
  }
  return -1;
}

int current(int cx, int cy)
{
  if (cx == 0) { return map[cy][cx].n; }
  if (map[cy][cx-1].n == 0) { return map[cy][cx].n; }
  return map[cy][cx-1].n;
}

int fall(int x1, int x2, int y, int *cx, int *cy)
{
  int x;
  char_t tmp;
  if (y == 0) return 0;

  if (x1 <= *cx && *cx <= x2+1 && y == *cy && current(*cx, *cy) == map[y][x1].n) { (*cy)--; }

  for (x = x1; x <= x2; x++) {
    tmp = map[y][x]; if (tmp.n == 0) return 0;
    map[y][x] = map[y-1][x];
    map[y-1][x] = tmp;
  }
  return 1;
}

int floating(int x1, int x2, int y)
{
  int x;
  if (y == 0) return 0;

  for (x = x1; x <= x2; x++) {
    if (map[y-1][x].n > 0) { return 0; }
  }
  return 1;
}

int fallsearch(int *cx, int *cy)
{
  int x, x2, y;
  int target, fallen = 0;

  for (y = 0; y < WIDTH; y++) {

    for (x = 0; x < WIDTH; x++) {
      if (map[y][x].n > 0) {
	target = map[y][x].n;
	for (x2 = x; x2 < WIDTH; x2++) {
	  if (map[y][x2].n != target) { break; }
	}
        if (x2 >= WIDTH) { break; }

	if (floating(x, x2-1, y)) {
	  fall(x, x2-1, y, cx, cy);
	  fallen = 1;
	}
	x = x2-1;
      }
    }

  }

  return fallen;
}

void concatenate()
{
  int x, x2, y;
  int max = (WIDTH-1), maxtmp, target;

  for (y = 0; y < WIDTH; y++) {

    for (x = 0; x <= max; x++) {
      if (map[y][x].n > 0) {
	for (x2 = x; ; x2++) {
	  if (map[y][x2].n == 0) { break; }
	  map[y][x2].n = map[y][x].n;
	}
	x = x2-1;
	maxtmp = x+1;
      }
    }

    max = maxtmp;
  }
}

int delete(int *x, int *y)
{
  int i;
  if (TAIL(*x, *y)) { return 0; }

  for (i = 0; ; i++) {
    if (map[*y][*x+i].n == 0) { break; }
    map[*y][*x+i] = map[*y][*x+i+1];
  }

  if (map[*y][*x].n == 0 && !TAIL(*x, *y)) {
    (*y)--; /* Notice! */
    if (*y < 0) { return 0; }
    if (map[*y][*x].n == 0 && !TAIL(*x, *y)) { return 0; }
  }

  return 1;
}

void leftmost(int *x, int *y)
{
  int target;

  if (TAIL(*x,*y)) { (*x)--; }

  for (; (*x) >= 0; (*x)--) { 
    if (map[*y][*x].n == 0) { (*x)++; break; }
  }
  if ((*x) < 0) *x = 0;
}

int main()
{
  int i, j, k, len;
  char s[WIDTH];
  int session, loop;
  int index;
  int x, y;
  int error;
  int target;

  gets(s); session = atoi(s);
  for (loop = 0; loop < session; loop++) {
    index = 1;
    x = 1;
    y = 0;
    error = 0;

    gets(s); len = strlen(s);
    for (i = 0; i < WIDTH; i++) {
      for (j = 0; j < WIDTH; j++) {
	map[i][j].c = '\0'; map[i][j].n = 0;
      }
    }
    map[0][0].c = s[0];
    map[0][0].n = 1;

    for (i = 1; i < len; i++) {
      switch (s[i]) {
      case 'F':
	if (TAIL(x,y)) { error = 1; break; }
	x++; break;
      case 'B':
	if (LEFTMOST(x,y)) { error = 1; break; }
	x--; break;
      case 'P':
	if (!MOVABLETO(x,y+1)) { error = 1; break; }
	y++; break;
      case 'N':
	if (!MOVABLETO(x,y-1)) { error = 1; break; }
	y--; break;
      case 'D':
	if (!delete(&x, &y)) { error = 1; break; }
	break;
      case 'C':
	if (TAIL(x,y)) { error = 1; break; }
	if (map[y+1][x].n > 0) { error = 1; break; }

	map[y+1][x].c = map[y][x].c;
	map[y+1][x].n = ++index;
	y++; x++;
	break;
      default:
	if (!(('0' <= s[i] && s[i] <= '9') ||
	      ('a' <= s[i] && s[i] <= 'z'))) { error = 1; break; }
	for (j = 0; ; j++) { if (TAIL(x+j,y)) break; }
	map[y][x].n = map[y][x+j-1].n;
	for (; j > 0; j--) {
	  map[y][x+j] = map[y][x+j-1];
	}
	map[y][x].c = s[i];
	x++;
	break;
      }
      if (error) break;
      while (1) { if (!fallsearch(&x, &y)) { break; } }
      concatenate();
      /*printf("%c -> ", s[i]);*/
      /*output(x,y);*/
    }
    /*    printf("%s -> ", s);*/
    if (error) printf("ERROR\n");
    else { 
      leftmost(&x, &y);
      target = map[y][x].n;
      for (i = 0; map[y][x+i].n == target; i++) { printf("%c", map[y][x+i].c); }
      printf("\n");
    }
  }

  return 0;
}