1. (2023·义乌模拟) 有如下Python程序段：

Q=[0]*10

cnt,head,tail = 0,0,0

S=input()

for i in range(0,9,2):

    t = S[i]

    n = int(S[i+1])

    if t == 'A':

        for j in range(n):

            Q[tail] = cnt

            tail += 1

            cnt += 1

    elif t == "D":

        while head != tail and n > 0:

            head += 1

            n -= 1

print(Q[head : tail])

若输入S的值为"A2D1A1D3A2"，则程序的输出结果是（   ）