-- SAMPLE 1 -- 4 1 3 1: c 2 1 2: i 3: c 4 3 4: X -- SAMPLE 2 -- 4 1 3 1: c 2 1 2: i 3: c 4 3 4: j -- SAMPLE 3 -- 11 1 4 1: a 2 2: b 3 1 3: X 4: a 5 5: b 6 8 6: f 7 7: Y 8: a 9 9: b 10 4 10: f 11 11: g