from collections import defaultdict

def main():
    N = int(input())
    d = defaultdict(list)
    for _ in range(N):
        i, *tmp = input().split()
        if i == '0':
            n, m, *A = tmp
            for a in A:
                d[int(n)].append(a)
        if i == '1':
            for j in range(1,21):
                if tmp[0] in d[j]:
                    d[j].remove(tmp[0])
                    print(j)
                    break
            else:
                print(-1)
        if i == '2':
            d[int(tmp[0])].clear()

if __name__ == "__main__":
    main()