#include <cstdio>
using namespace std;
typedef long long ll;
const int N = 500005;
struct Info {
	int x;
	ll cnt;
	Info() {
		x = cnt = 0;
	}
	Info(int a) {
		x = a;
		cnt = 1;
	}
	Info(int a, ll b) {
		x = a;
		cnt = b;
	}
};
Info operator + (const Info & a, const Info & b) {
	if (a.x == b.x) {
		return Info(a.x, a.cnt + b.cnt);
	} else {
		if (a.cnt >= b.cnt) {
			return Info(a.x, a.cnt - b.cnt);
		} else {
			return Info(b.x, b.cnt - a.cnt);
		}
	}
}
Info & operator += (Info & a, const Info & b) {
	return a = a + b;
}
struct SegmentTreeNode {
	int ch[2], sz;
	Info w;
} segmenttreenode[N * 50];
int root[N * 2], segmenttreenodecnt;
void push_up(int p) {
	segmenttreenode[p].sz = segmenttreenode[segmenttreenode[p].ch[0]].sz + segmenttreenode[segmenttreenode[p].ch[1]].sz;
	segmenttreenode[p].w = segmenttreenode[segmenttreenode[p].ch[0]].w + segmenttreenode[segmenttreenode[p].ch[1]].w;
}
void insert(int & p, int x, int d = 1, int l = 0, int r = 1000000) {
	if (p == 0) {
		segmenttreenodecnt++;
		p = segmenttreenodecnt;
	}
	if (l == r) {
		segmenttreenode[p].w.x = x;
		segmenttreenode[p].w.cnt += d;
		segmenttreenode[p].sz += d;
	} else {
		int mid = (l + r) / 2;
		if (x <= mid) {
			insert(segmenttreenode[p].ch[0], x, d, l, mid);
		} else {
			insert(segmenttreenode[p].ch[1], x, d, mid + 1, r);
		}
		push_up(p);
	}
}
int query(int p, int x, int l = 0, int r = 1000000) {
	if (p == 0) {
		return 0;
	}
	if (l == r) {
		return segmenttreenode[p].w.cnt;
	} else {
		int mid = (l + r) / 2;
		if (x <= mid) {
			return query(segmenttreenode[p].ch[0], x, l, mid);
		} else {
			return query(segmenttreenode[p].ch[1], x, mid + 1, r);
		}
	}
}
void merge(int & x, int y, int l = 0, int r = 1000000) {
	if (x == 0 || y == 0) {
		x |= y;
	} else if (l == r) {
		segmenttreenode[x].w += segmenttreenode[y].w;
		segmenttreenode[x].sz += segmenttreenode[y].sz;
	} else {
		int mid = (l + r) / 2;
		merge(segmenttreenode[x].ch[0], segmenttreenode[y].ch[0], l, mid);
		merge(segmenttreenode[x].ch[1], segmenttreenode[y].ch[1], mid + 1, r);
		push_up(x);
	}
}
struct LinkListNode {
	int val, nxt;
} linklistnode[N * 2];
int head[N * 2], tail[N * 2], linklistnodecnt;
int opt3_x[N];
int main() {
//	freopen("in.txt", "r", stdin);
	int n, q;
	scanf("%d %d", &n, &q);
	for (int l, i = 1; i <= n; i++) {
		scanf("%d", &l);
		if (l != 0) {
			head[i] = linklistnodecnt + 1;
			for (int x; l != 0; l--) {
				scanf("%d", &x);
				linklistnodecnt++;
				linklistnode[linklistnodecnt].nxt = tail[i];
				linklistnode[linklistnodecnt].val = x;
				tail[i] = linklistnodecnt;
				insert(root[i], x);
			}
		}
	}
	for (int op, x, y, m, x1, x2, x3; q != 0; q--) {
		scanf("%d", &op);
		if (op == 1) {
			scanf("%d %d", &x, &y);
			insert(root[x], y);
			linklistnodecnt++;
			linklistnode[linklistnodecnt].nxt = tail[x];
			linklistnode[linklistnodecnt].val = y;
			tail[x] = linklistnodecnt;
			if (head[x] == 0) {
				head[x] = linklistnodecnt;
			}
		} else if (op == 2) {
			scanf("%d", &x);
			if (linklistnode[tail[x]].val == 0) {
				return 114514;
			}
			insert(root[x], linklistnode[tail[x]].val, -1);
			tail[x] = linklistnode[tail[x]].nxt;
			if (tail[x] == 0) {
				head[x] = 0;
			}
		} else if (op == 3) {
			scanf("%d", &m);
			Info res;
			ll tot_len = 0;
			for (int i = 1; i <= m; i++) {
				scanf("%d", &opt3_x[i]);
				tot_len += segmenttreenode[root[opt3_x[i]]].sz;
				res += segmenttreenode[root[opt3_x[i]]].w;
			}
			ll cnt = 0;
			for (int i = 1; i <= m; i++) {
				cnt += query(root[opt3_x[i]], res.x);
			}
			if (cnt > tot_len / 2) {
				printf("%d\n", res.x);
			} else {
				printf("-1\n");
			}
		} else {
			scanf("%d %d %d", &x1, &x2, &x3);
			if (head[x1] != 0 && head[x2] != 0) {
				if (head[x1] == 0) {
					head[x3] = head[x2];
					tail[x3] = tail[x2];
					root[x3] = root[x2];
				} else if (head[x2] == 0) {
					head[x3] = head[x1];
					tail[x3] = tail[x1];
					root[x3] = root[x1];
				} else {
					merge(root[x1], root[x2]);
					root[x3] = root[x1];
					head[x3] = head[x1];
					tail[x3] = tail[x2];
					linklistnode[head[x2]].nxt = tail[x1];
				}
			}
		}
	}
	return 0;
}