Task: Program Execution
Input (English): 9907 b v r 1007 2015 z a q q 4671 m 6507 r 7169 c c 4253 8237 z 8227 4521 9377 8109 1893 4639 t 5631 a x v t c 8653
Output (English): a, b, c, m, q, r, t, v, x, z