from collections import deque
from collections import 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]

    cust = defaultdict(deque)
    through = []
    for s in U:
        if s[0] == '0':
            for t in s[3:]:
                cust[t].append(int(s[1]))
        elif s[0] == '1':
            while cust[s[1]]:
                seat = cust[s[1]].popleft()
                if seat not in through:
                    print(seat)
                    break
            else:
                print(-1)
        elif s[0] == '2':
            through.append(int(s[1]))

main()