#include <stdio.h>
#include <string.h>

int main (void)
{
  int K, k;
  char occ[51];
  char s[31];
  int x, y, x1, x2, m;
  char f;
  int nd;
  int t[51];

  FILE *in = fopen ("limit.in", "r");

  fscanf (in, "%d\n", &K);
  for (k = 1; k <= K; k ++)
    {
      printf ("Data Set %d:\n", k);
      for (x = 0; x < 51; x ++) occ[x] = -1;
      nd = 0; x = 0; y = 0;
      fgets (s, 30, in); s[strlen(s)-1] = 0;
      while (strcmp (s, "endprogram") != 0)
	{
	  if (strcmp (s, "basic") == 0) if (y > occ[x]) occ[x] = y; else;
	  else if (strcmp (s, "endloop") == 0)
	  { 
	    if (t[nd-1] == 1) x --;
	    else if (t[nd-1] == -1) y --;
	    nd --;
	  }
	  else if (s[5] == 'x') { t[nd] = 1; nd ++; x ++; }
	  else if (s[5] == 'y') { t[nd] = -1; nd ++; y ++; }
	  else { t[nd] = 0; nd ++; }
 	  fgets (s, 30, in); s[strlen(s)-1] = 0;
	}
      m = -1;
      for (x = 50; x >= 0; x --)
	if (occ[x] <= m) occ[x] = -1;
	else m = occ[x];
      for (x1 = 0; x1 < 51; x1 ++) if (occ[x1] >= 0)
	for (x2 = x1 + 2; x2 < 51; x2 ++) if (occ[x2] >= 0)
	  for (x = x1 + 1; x < x2; x ++) 
	    if (((float) occ[x]) <= (float) occ[x1] 
		+ ((float)(x-x1)) * ((float)(occ[x2]-occ[x1])) / ((float) (x2-x1)))
	      occ [x] = -1;	    
      f = 1;
      for (x = 50; x >= 0; x --)
	  if (occ[x] >= 0)
	    {
	      if (!f) printf (" + ");
	      f = 0;
	      if (x == 0 && occ[x] == 0) printf ("1");
	      else
		{ 
		  if (x == 1) printf ("x");
		  else if (x >= 2) printf ("x^%d", x);
		  if (occ[x] == 1) printf ("y");
		  else if (occ[x] >= 2) printf ("y^%d", occ[x]);
		}
	    }
      if (f) printf ("0");
      printf ("\n\n");
      fscanf (in, "\n");
    }

  fclose (in);
  return 0;
}