#include <stdio.h>

#define BOARD 20
#define ROWS 10
#define COLUMNS 20
#define CH '#'
#define EMPTY '-'

int main() {

int i, j;

for (i=1; i<= ROWS/2; i=i+1) {

 /* print a string of 20 '#'  */
   for(j=1; j<=COLUMNS/2; j=j+1) {
     printf("%c",CH);
     printf("%c", EMPTY); 
   }
   printf("\n"); 

   for(j=1; j<=COLUMNS/2; j=j+1) {
     printf("%c",EMPTY);
     printf("%c", CH); 
   }
   printf("\n"); 

}


return 0;
}