Task: Program Execution
Input (English): QGPqnddlmUZlRQBPbDzXAGIYxniabOShFx, TEuCHOZlRQBPbDzXAGZLa
Output (English): a, b, d, f, g, h, i, l, m, n, o, p, q, r, s, u, x, y, z