#include<bits/stdc++.h>
using namespace std;

#define PII pair<int, int>
#define VI vector<int>
#define VPII vector<PII>
#define LL long long
#define f first
#define s second
#define MP make_pair
#define PB push_back
#define LD long double
#define endl '\n'
#define ALL(c) (c).begin(), (c).end()
#define SIZ(c) (int)(c).size()
#define REP(i, n) for (int i = 0; i < (int)(n); i++)
#define FOR(i, b, e) for (int i = (b); i <= (int)(e); i++)
#define FORD(i, b, e) for (int i = (b); i >= (int)(e); i--)
#define ll LL
#define mp MP
#define pb PB
#define st f
#define nd s
#define eb emplace_back
const int inf = 1e9 + 7;
const LL INF = 1e18L + 7;

#define sim template<class n
sim, class s> ostream & operator << (ostream &p, pair<n, s> x)
{return p << "<" << x.f << ", " << x.s << ">";}
sim> auto operator << (ostream &p, n y) ->
typename enable_if<!is_same<n, string>::value, decltype(y.begin(), p)>::type
{int o = 0; for (auto c : y) {if (o++) p << ", "; p << c;} return p << "}";}
void dor() {cerr << endl;}
sim, class...s> void dor(n p, s...y) {cerr << p << " "; dor(y...);}
sim, class s> void mini(n &p, s y) {if (p > y) p = y;}
sim, class s> void maxi(n &p, s y) {if (p < y) p = y;}

#ifdef DEB
#define debug(...) dor(__FUNCTION__, ":", __LINE__, ": ", __VA_ARGS__)
#else
#define debug(...)
#endif

#define I(x) #x " =", (x), " "
#define A(a, i) #a "[" #i " =", i, "] =", a[i], " "

const int N = 1<<17;

int n, q;

int t[N];
int x[N];
int y[N];
int v[N];
int ans[N];

map<PII, PII> M;

struct E
{
	int a, b, w;
};

vector<E> load[2*N];

struct dsu
{
	int rep[N];
	int siz[N];
	
	VPII roll;
	
	int Find(int a)
	{
		if(a!=rep[a])
			return Find(rep[a]);
		else
			return a;
	}
	
	void Union(int a, int b)
	{
		a = Find(a);
		b = Find(b);
	
		roll.eb(a, siz[a]);
		roll.eb(b, siz[b]);
		
		if(a==b)
			return;
		
		if(siz[a]>siz[b])
			swap(a, b);
		
		rep[a] = b;
		siz[b] += siz[a];			
	}
	
	void rollback()
	{
		rep[roll.back().st] = roll.back().st;
		siz[roll.back().st] = roll.back().nd;
		roll.pop_back();
	}
};

dsu D[10];

void insert(int a, int b, E c, int v = 1, int l = 0, int r = N-1)
{
	if(a>r || l>b)
		return;
		
	if(a<=l && r<=b)
	{
		load[v].pb(c);
		return;
	}
	
	insert(a, b, c, 2*v, l, (l+r)/2);
	insert(a, b, c, 2*v+1, (l+r)/2+1, r);
}

void dfs(int u = 1, int l = 0, int r = N-1)
{
	for(auto it:load[u])
	{
		for(int j = it.w; j < 10; ++j)
		{
			D[j].Union(it.a, it.b);
		}
	}
	
	if(l==r && l<q && t[l]==2)
	{
		ans[l] = -1;
		
		for(int i = 0; i < 10; ++i)
		{
			if(D[i].Find(x[l])==D[i].Find(y[l]))
			{
				ans[l] = i;
				break;
			}
		}
	}
	
	if(l != r)
		{
		dfs(2*u, l, (l+r)/2);
		dfs(2*u+1, (l+r)/2+1, r);
		}
	
	for(auto it:load[u])
	{
		for(int j = it.w; j < 10; ++j)
		{
			D[j].rollback();
			D[j].rollback();
		}
	}
	
	
}

int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(NULL);
	
	cin >> n >> q;
	
	for(int i = 0; i < q; ++i)
	{	
		cin >> t[i];
		
		if(t[i]==0)
		{
			cin >> x[i] >> y[i] >> v[i];
			
			if(x[i]>y[i])
				swap(x[i], y[i]);
			
			M[{x[i], y[i]}] = mp(i, v[i]);
		}
		else if(t[i]==1)
		{
			cin >> x[i] >> y[i];
			
			if(x[i]>y[i])
				swap(x[i], y[i]);
			
			auto m = M[{x[i], y[i]}];
				
			insert(m.st, i-1, (E){x[i], y[i], m.nd});
			
			M[{x[i], y[i]}] = mp(-1, -1);
		}
		else
		{
			cin >> x[i] >> y[i];
		}
	}
	
	for(auto it:M)
	{
		if(it.nd!=mp(-1, -1))
		{
			auto m = it.nd;
		
			insert(m.st, q-1, (E){it.st.st, it.st.nd, m.nd});
		}
	}
	
	for(int i = 0; i < 10; ++i)
	{
		for(int j = 0; j < n; ++j)
		{
			D[i].rep[j] = j;
			D[i].siz[j] = 1;
		}
	}
	
	dfs();
	
	for(int i = 0; i < q; ++i)
	{
		if(t[i]==2)
			cout << ans[i] << endl;
	}
}