[백준] 1406번 : 에디터 with python3

import sys

f = lambda : sys.stdin.readline().rstrip()

left = [i for i in f()]
right = list()

for _ in range(int(f())):
    order = f().split()
    if order[0] == "L" and left:
        right.append(left.pop())
    elif order[0] == "D" and right:
        left.append(right.pop())
    elif order[0] == "B" and left:
        left.pop()
    elif order[0] == "P":
        left.append(order[1])

print(''.join(left + right[::-1]))