第二道题解答 ``` import sys s = sys.stdin.readline().strip() out = 0 all_dict = {"0_0_0":0} r,e,d = 0,0,0 for p,item in enumerate(s): if item == "r": r += 1 elif item == "e": e += 1 else: d += 1 list = str(r)+"_"+str(e)+"_"+str(d) min_number = min([r,e,d]) for i in range(1,min_number+1): if str(r-i)+"_"+str(e-i)+"_"+str(d-i) in all_dict: out += 1 all_dict[list] = 1 print(out) ```