BOJ - 5397 - 키로거

import sys

def solution():
    T = int(sys.stdin.readline())
    for _ in range(T):
        L = sys.stdin.readline().strip()
        s, e = [], []

        for l in L:
            if l == '<':
                if s:
                    e.append(s.pop())
            elif l == '>':
                if e:
                    s.append(e.pop())
            elif l == '-':
                if s:
                    s.pop()
            else:
                s.append(l)
        s.extend(reversed(e))

        print(''.join(s))

solution()

https://www.acmicpc.net/problem/5397