from collections import deque, defaultdict from sys import stdin, stdout input = lambda: stdin.readline().rstrip() write = stdout.write def main(): N = int(input()) U = [tuple(input().split()) for _ in [0] * N] sushi = defaultdict(deque) kaikei = [] for s in U: if s[0] == '0': for t in s[3:]: sushi[t].append(s[1]) elif s[0] == '1': while sushi[s[1]]: seat = sushi[s[1]].popleft() if seat not in kaikei: print(seat) break else: print(-1) elif s[0] == '2': kaikei.append(s[1]) main()