#include <stdio.h>

int main (void)
{
  int k, K;
  int n, i, j, t;
  char matches;
  char s[1003];
  char y[101][1002];
  int c[1002];

  FILE *in = fopen ("biomed.in", "r");
  fscanf (in, "%d\n", &K);
  for (k = 1; k <= K; k ++)
    {
      fscanf (in, "%d\n", &n);
      fgets (s, 1003, in); s[strlen(s)-1] = 0; 
      for (i = 0; i < n; i ++)
	{ fgets (y[i], 1003, in); y[i][strlen(y[i])-1] = 0; }
      c[0] = 0;
      for (i = 1; i <= strlen(s); i ++)
	{
	  c[i] = strlen(s)+1;
	  for (j = 0; j < n; j ++)
	    if (strlen(y[j]) <= i)
	      {
		matches = 1;
		for (t = 0; t < strlen(y[j]); t ++)
		  if (y[j][t] != s[i-strlen(y[j])+t]) matches = 0;
		if (matches && (c[i-strlen(y[j])]+1 < c[i]))
		  c[i] = c[i-strlen(y[j])]+1;
	      }
	}
      printf ("Data Set %d:\n", k);
      if (c[strlen(s)] < strlen(s)+1)
	printf ("%d\n", c[strlen(s)]);
      else printf ("Impossible\n");
    }
  fclose (in);
  return 0;
}