コード # coding:utf-8 def letter_queue(c): r = [] for i in c: s = i.split() if len(s) == 2 and s[0] == "PUSH": r.extend(s[1]) if len(s) == 1 and r != []: r = r[1:] if r == []: return "" else: return "".join(r) if __name__ == '__main__': le…