lst = [[] for _ in range(21)]
n = int(input())
for _ in range(n):
    i,*a, = input().split()
    if i=="0":
        lst[int(a[0])] = a[2:]
    elif i=="1":
        b = a[0]
        for j in range(1,21):
            if b in lst[j]:
                lst[j].pop(lst[j].index(b))
                print(j)
                break
        else:
            print(-1)
    elif i=="2":
        lst[int(a[0])] = []