#include <stdio.h>
#include <math.h>

int main (void)
{
  int k, K, s, i, j;
  int w, h, t;
  int x, y;
  int xx, yy, tt;
  int a[101][11][11];
  int dd[101][11][11];

  FILE *in = fopen ("sharks.in", "r");
  fscanf (in, "%d\n", &K);
  for (k = 1; k <= K; k ++)
    {
      fscanf (in, "%d %d %d %d\n", &w, &h, &t, &s);
      for (tt = 1; tt <= t; tt ++)
	for (xx = 1; xx <= w; xx ++)
	  for (yy = 1; yy <= h; yy ++)
	    dd[tt][xx][yy] = 2*(w*w+h*h);
      for (i = 0; i < s; i ++)
	{
	  fscanf (in, "%d %d %d\n", &x, &y, &tt);
	  for (xx = 1; xx <= w; xx++)
	    for (yy = 1; yy <= w; yy ++)
	      if ((xx-x)*(xx-x) + (yy-y)*(yy-y) < dd[tt][xx][yy])
		dd[tt][xx][yy] = (xx-x)*(xx-x) + (yy-y)*(yy-y);
	}
      for (xx = 1; xx <= w; xx ++)
	for (yy = 1; yy <= h; yy ++)
	  a[1][xx][yy] = -2*(h*h+w*w);
      a[1][1][1] = dd[1][1][1];
      for (tt = 2; tt <= t; tt ++)
	for (xx = 1; xx <= w; xx ++)
	  for (yy = 1; yy <= h; yy ++)
	    {
	      int aa = a[tt-1][xx][yy];
	      if (xx > 1 && a[tt-1][xx-1][yy] > aa)
		aa = a[tt-1][xx-1][yy];
	      if (xx < w && a[tt-1][xx+1][yy] > aa)
		aa = a[tt-1][xx+1][yy];
	      if (yy > 1 && a[tt-1][xx][yy-1] > aa)
		aa = a[tt-1][xx][yy-1];
	      if (yy < h && a[tt-1][xx][yy+1] > aa)
		aa = a[tt-1][xx][yy+1];
	      if (dd[tt][xx][yy] < aa)
		aa = dd[tt][xx][yy];
	      a[tt][xx][yy] = aa;
	    }
      printf ("Data Set %d:\n", k);
      printf ("%.2f\n", sqrt((double) a[t][1][1]));
    }
  fclose (in);
  return 0;
}