(red) string and crisscross the top (black) string through the new bead added.
continue to pass the red string (the one you just used to added new bead on) through one old bead from step 11 marked with a.
add two gray beads on the bottom (black) string and crisscross the top (red) string through the last bead added.
continue to pass the black string (the one you just used to add new beads on) through two old beads from step 12 and 13 marked with a and b.
add three gray beads on the left (red) string, crisscross the right (black) string through the last bead added.
continue to pass the red string (the 