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

char *atos(char **a)
{
  int i, size;
  char *rv;

  size = 1;
  for (i = 0; a[i] != NULL; i++) size += (strlen(a[i])+1);
  rv = (char *) malloc(sizeof(char)*size);

  size = 0;
  rv[0] = '\0';

  for (i = 0; a[i] != NULL; i++) {
    if (i != 0) {
      rv[size] = ' ';
      size++;
    }
    strcpy(rv+size, a[i]);
    size += strlen(a[i]);
  }
  return rv;
}

main(int argc, char **argv)
{
  char *s;

  s = atos(argv);
  printf("%s\n", s);
}