@array1 = (1, 2, 3, 1, 2, 3, 1, 2, 3 );
@array2 = (blue, white, yellow, blue, white, yellow, blue, white, yellow);
while (@array1) {
 (@p1) = (shift(@array1), shift(@array1), shift(@array1));
 (@p2) = (shift(@array2), shift(@array2), shift(@array2));
 printf("%s %s %s   %s %s %s\n", (@p1), (@p2));
}