#include <string>
#include <vector>
#include <list>
#include <cmath>
#include <algorithm>
#include <map>
#include <set>
#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;

void usage(const string s)
{
  fprintf(stderr, "usage: grid-graph rows columns seed\n");
  if (s != "") fprintf(stderr, "%s\n", s.c_str());
  exit(1);
}

int main(int argc, char **argv)
{
  int rows, cols, i, j, n;
  long seed;
  double w, h;

  /* Parse and error check the command line. */

  if (argc != 4) usage("");
  rows = atoi(argv[1]);
  if (rows <= 1) usage("Rows must be > 1");
  cols = atoi(argv[2]);
  if (cols <= 1) usage("Rows must be > 1");
  if (sscanf(argv[3], "%ld", &seed) == 0) usage("Seed must be a number");
  
  srand48(seed);
  w = (cols > 10) ? 10 : cols - 1;
  w /= (double) (cols-1);
  h = (rows > 10) ? 10 : rows - 1;
  h /= (double) (rows-1);
  
  for (i = 0; i < rows; i++) {
    for (j = 0; j < cols; j++) {
      printf("%.4lf %.4lf\n", ((double) j) * w, ((double) i) * h);
    }
  }
  printf("Edges\n");

  n = 0;
  for (i = 0; i < rows; i++) {
    for (j = 0; j < cols; j++) {
      if (j != 0 && drand48() < .5) printf("%d\n", n*rows*cols+n-1);
      if (i != 0 && drand48() < .5) printf("%d\n", n*rows*cols+n-cols);
      if (j != 0 && i != 0 && drand48() < .5) printf("%d\n", n*rows*cols+n-cols-1);
      if (j != cols-1 && i != 0 && drand48() < .5) printf("%d\n", n*rows*cols+n-cols+1);
      n++;
    }
  }
  return 0;
}