import sys

class LinkList(object):
    def __init__(self):
        super().__init__()
        self.head = -1
        self.idx = 1
        self.e  = [0] * 100010
        self.ne = [0] * 100010

    def insert(self, *args):
        if len(args) == 1:
            x = args[0]
            self.e[self.idx] = x
            self.ne[self.idx] = self.head
            self.head = self.idx
            self.idx += 1
        else:
            k, x = args
            self.e[self.idx] = x
            self.ne[self.idx] = self.ne[k]
            self.ne[k] = self.idx
            self.idx += 1

    def remove(self,k):
        if k == 0 and self.head != -1:
            self.head = self.ne[self.head]
        elif k != 0 and self.ne[k] != -1:
            self.ne[k] = self.ne[self.ne[k]]

    def traverse(self):
        i = self.head
        ret = []
        while(i != -1):
            ret.append(self.e[i])
            i = self.ne[i]
        return ret

if __name__ == '__main__':
    m = int(sys.stdin.readline())
    ll = LinkList()
    for _ in range(m):
        op, *args = list(sys.stdin.readline().strip().split())
        args = list(map(int, args))
        if op == 'H' or op == 'I':
            ll.insert(*args)
        elif op == 'D':
            ll.remove(*args)
    print(" ".join(map(str, ll.traverse())))