#include<bits/stdc++.h>
using namespace std;
#define fr(ii,ss,tt) for(int ii=ss;ii<=tt;ii++)
#define rf(ii,ss,tt) for(int ii=ss;ii>=tt;ii--)
#define pii pair<int,int>
#define pt printf
#define x first
#define y second
#define siz(x) ((int)size(x))
#define pb push_back
#define eb emplace_back
#define all(a) begin(a),end(a)
#define input(f) freopen(f,"r",stdin)
#define output(f) freopen(f,"w",stdout)
template<typename T>bool tomax(T&x,const T&y) {
    if(x<y)return x=y,true;
    return false;
}
template<typename T>bool tomin(T&x,const T&y) {
    if(x>y)return x=y,true;
    return false;
}
#define gc() getchar()
#define pc(c) putchar(c)
inline void rd(auto&x,auto&...y) {
    char ch;
    bool f=0;
    while(!isdigit(ch=gc()))if(ch=='-')f=1;
    x=0;
    do {
        x=(x<<1)+(x<<3)+(ch^48);
    } while(isdigit(ch=gc()));
    if(f)x=-x;
    if constexpr(sizeof...(y))rd(y...);
}
#ifndef ONLINE_JUDGE
#define DF(T) void prt(T x){cout<<x;}
DF(int)DF(char)DF(string)DF(bool)DF(long long)DF(unsigned int)
void prt(auto x);
void prt(pair<auto,auto> x) {
    pc('{');
    prt(x.first);
    pc(',');
    prt(x.second);
    pc('}');
}
void pp(auto x,auto y) {
    pc('{');
    for(; x!=y; ++x) {
        prt(*x);
        pc(',');
    }
    printf("\b}");
}
void pp(auto x,int y) {
    prt(x,x+y);
}
void prt(auto x) {
    pp(begin(x),end(x));
}
void pl(auto x,auto...y) {
    prt(x);
    if constexpr(sizeof...(y))pl(y...);
    else pc('\n');
}
void ppl(auto x,auto xx,auto...y) {
    pp(x,xx);
    if constexpr(sizeof...(y))ppl(y...);
    else pc('\n');
}
#define Z(x...) cout<<#x<<":",pl(x)
#define ZZ(x...) cout<<#x<<":",ppl(x)
#else
#define Z(...)
#define ZZ(...)
#endif
#define int long long
const int N=2e6+6,S=19;
mt19937 gen(chrono::steady_clock::now().time_since_epoch().count());
int n,q;
list<int>a[N];
struct Node{
    int c[2];
    int sz;
}t[N*(S+2)];int rt[N],tot;
#define c(i,j) t[i].c[j]
#define sz(i) t[i].sz
int merge(int x,int y){
    if(!x||!y){
        return x+y;
    }
    sz(x)+=sz(y);
    c(x,0)=merge(c(x,0),c(y,0));
    c(x,1)=merge(c(x,1),c(y,1));
    return x;
}
void add(int i,int p,int v){
    int*c=&rt[i];
    rf(b,S,-1){
        int&cur=*c;
        if(!cur)cur=++tot;
        sz(cur)+=v;
        if(b==-1)return;
        c=&c(cur,p>>b&1);
    }
}
int ask(vector<int>T){
    long long nn=0;
    for(int&i:T){
        nn+=a[i].size();
        i=rt[i];
    }
    int ret=0;
    fr(_,0,S){
        long long ls=0,rs=0;
        for(int i:T){
            ls+=sz(c(i,0));
            rs+=sz(c(i,1));
        }
        if(ls>nn/2){
            ret=(ret<<1);
            for(int&i:T)i=c(i,0);
        }else if(rs>nn/2){
            ret=(ret<<1|1);
            for(int&i:T)i=c(i,1);
        }else{
            return -1;
        }
    }
    return ret;
}
void ins(int i,int v) {
    a[i].eb(v);
    add(i,v,1);
}
void del(int i) {
    add(i,a[i].back(),-1);
    a[i].pop_back();
}
signed main() {
    rd(n,q);
    fr(i,1,n) {
        int l;
        rd(l);
        while(l--) {
            int v;
            rd(v);
            ins(i,v);
        }
    }
    while(q--) {
        int o,x,y,z,m;
        vector<int>t;
        rd(o);
        if(o==1) {
            rd(x,y);
            ins(x,y);
        }
        if(o==2) {
            rd(x);
            del(x);
        }
        if(o==3) {
            int l;
            rd(l);
            t.resize(l);
            fr(i,0,l-1){
                rd(t[i]);
            }
            pt("%d\n",ask(t));
        }
        if(o==4) {
            rd(x,y,z);
            rt[z]=merge(rt[x],rt[y]);

            m=0;
            if(a[x].size()>a[y].size())swap(x,y),m=1;
            a[z].swap(a[y]);
            for(auto e:a[x]) {
                m==0?a[z].push_front(e):a[z].push_back(e);
            }
            move(a[x]);

        }
    }
    return 0;
}