#include <stdio.h>

#define WIDTH 600
#define HEIGHT 600
#define HALFPOINT 300

#define CYAN 0, 255, 255
#define GREEN 0, 255, 0
#define RED 255, 0, 0


int main() {

  int i,j; 

/* Step 1. Output the header information    */

  printf("P6\r\n");                  /* magic number */
  printf("%d %d\r\n", WIDTH, HEIGHT);  /* image size */
  printf("255\n");           /* max color value */
 
for(j=1;j<=HALFPOINT;j++){  
  for (i=1;i<=HALFPOINT; i++){
      printf("%c%c%c", RED);
  }
  for (i=1; i<=HALFPOINT; i++) {
      printf("%c%c%c",GREEN);
  }
}
for(j=1;j<=HALFPOINT;j++){  
  for (i=1;i<=HALFPOINT; i++){
      printf("%c%c%c", GREEN);
  }
  for (i=1; i<=HALFPOINT; i++) {
      printf("%c%c%c",RED);
  }
}


 return 0;
}


/*
  do HEIGHT TIMES
    print one row :  do WIDTH times
                        print one pixel

*/