Problem: Given a tree with n (1 ≤ n ≤ 200,000) nodes and a list of q (1 ≤ q ≤ 100,000) queries, process the queries in order and output a value for each output query. The given tree is connected and each node on the tree has a weight wi (-10,000 ≤ wi ≤ 10,000).

Each query consists of a number ti (ti = 1, 2), which indicates the type of the query , and three numbers ai, bi and ci (1 ≤ ai, bi ≤ n, -10,000 ≤ ci ≤ 10,000). Depending on the query type, process one of the followings:

* (ti = 1: modification query) Change the weights of all nodes on the shortest path between ai and bi (both inclusive) to ci.

* (ti = 2: output query) First, create a list of weights on the shortest path between ai and bi (both inclusive) in order. After that, output the maximum sum of a non-empty continuous subsequence of the weights on the list. ci is ignored for output queries.



Input

The first line contains two integers n and q. On the second line, there are n integers which indicate w1, w2, ... , wn.

Each of the following n - 1 lines consists of two integers si and ei (1 ≤ si, ei ≤ n), which means that there is an edge between si and ei.

Finally the following q lines give the list of queries, each of which contains four integers in the format described above. Queries must be processed one by one from top to bottom.

Output

For each output query, output the maximum sum in one line.

Examples

Input

3 4
1 2 3
1 2
2 3
2 1 3 0
1 2 2 -4
2 1 3 0
2 2 2 0


Output

6
3
-4


Input

7 5
-8 5 5 5 5 5 5
1 2
2 3
1 4
4 5
1 6
6 7
2 3 7 0
2 5 2 0
2 4 3 0
1 1 1 -1
2 3 7 0


Output

12
10
10
19


Input

21 30
10 0 -10 -8 5 -5 -4 -3 1 -2 8 -1 -7 2 7 6 -9 -6 3 4 9
10 3
3 2
3 12
12 4
4 13
4 9
10 21
21 1
1 11
11 14
1 15
10 6
6 17
6 16
6 5
5 18
5 19
10 7
10 8
8 20
1 1 21 -10
1 3 19 10
2 1 13 0
1 4 18 8
1 5 17 -5
2 16 7 0
1 6 16 5
1 7 15 4
2 4 20 0
1 8 14 3
1 9 13 -1
2 9 18 0
1 10 12 2
1 11 11 -8
2 21 15 0
1 12 10 1
1 13 9 7
2 6 14 0
1 14 8 -2
1 15 7 -7
2 10 2 0
1 16 6 -6
1 17 5 9
2 12 17 0
1 18 4 6
1 19 3 -3
2 11 8 0
1 20 2 -4
1 21 1 -9
2 5 19 0


Output

20
9
29
27
10
12
1
18
-2
-3

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
template<class T> using vec = vector<T>;
template<class T> using vvec = vector<vec<T>>;

template<typename Monoid,typename OperatorMonoid,typename F,typename G,typename H>
struct LazySegmentTree {
	int sz,height;
	vec<Monoid> data;
	vec<OperatorMonoid> lazy;
	const F op;
	const G homo;
	const H comp;
  	const Monoid e;
	const OperatorMonoid Oe;

	LazySegmentTree(int n,const F op,const G homo,const H comp,
					const Monoid &e,const OperatorMonoid Oe)
		: op(op),homo(homo),comp(comp),e(e),Oe(Oe) {
		sz = 1;
		height = 0;
		while(sz<=n) sz <<= 1,height++;
		data.assign(2*sz,e);
		lazy.assign(2*sz,Oe);
	}

	void set(int k,const Monoid &x) {
		data[k+sz] = x;
	}

	void build() {
		for(int k=sz-1;k>0;k--) {
			data[k] = op(data[2*k], data[2*k+1]);
		}
	}

	inline void propagate(int k) {
		if(lazy[k]!=Oe) {
			lazy[2*k] = comp(lazy[2*k], lazy[k]);
			lazy[2*k+1] = comp(lazy[2*k+1], lazy[k]);
			data[k] = reflect(k);
			lazy[k] = Oe;
		}
	}

	inline Monoid reflect(int k) {
		return lazy[k] == Oe? data[k]:homo(data[k],lazy[k]);
	}

	inline void recalc(int k) {
		while(k>>=1) data[k] = op(reflect(2*k), reflect(2*k+1));
	}

	inline void thrust(int k) {
		for(int i=height;i>0;i--) propagate(k>>i);
	}

	void update(int a, int b, const OperatorMonoid &x) {
		thrust(a+=sz);
		thrust(b+=sz-1);
		for(int l=a,r=b+1;l<r;l>>=1,r>>=1) {
			if(l&1) lazy[l] = comp(lazy[l],x),++l;
			if(r&1) --r, lazy[r] = comp(lazy[r],x);
		}
		recalc(a);
		recalc(b);
	}

	Monoid query(int a, int b) {
		thrust(a+=sz);
		thrust(b+=sz-1);
		Monoid L = e, R = e;
		for(int l=a, r=b+1;l<r;l>>= 1,r>>=1) {
			if(l&1) L = op(L,reflect(l++));
			if(r&1) R = op(reflect(--r),R);
		}
		return op(L,R);
	}

	Monoid operator[](const int &k) {
		return query(k,k+1);
	}
};

struct edge{
    int to,id;
    ll dist;
    edge(int to,ll dist=1,int id=1):to(to),id(id),dist(dist){};
};

class HeavLightDecomposition{
private:
    vvec<edge> g;
    vec<int> sz,in,out,head,par;
    int pos;

    void dfs_sz(int cur,int p){
        sz[cur] = 1;
        par[cur] = p;
        for(auto& e:g[cur]) if(e.to!=p){
            dfs_sz(e.to,cur);
            sz[cur] += sz[e.to];
            if(sz[e.to]>sz[g[cur][0].to]) swap(e,g[cur][0]);
        }
    }

    void dfs_hld(int cur,int p){
        in[cur] = pos++;
        for(auto& e:g[cur]) if(e.to!=p){
            head[e.to] = (e.to==g[cur][0].to? head[cur]:e.to);
            dfs_hld(e.to,cur);
        }
        out[cur] = pos;
    }
public:
    HeavLightDecomposition(){}
    HeavLightDecomposition(int N,int root,vvec<edge> tree):
    g(tree),sz(N),in(N),out(N),head(N),par(N){
        pos = 0;
        dfs_sz(root,-1);
        dfs_hld(root,-1);
    }

    int lca(int u,int v){
        while(true){
            if(in[u]>in[v]) swap(u,v);
            if(head[u]==head[v]) return u;
            v = par[head[v]];
        }
    }

    template<class T,class G>
    void update(int u,int v,const T& x,const G& g, bool isedge=false){
        while(true){
            if(in[u]>in[v]) swap(u,v);
            if(head[u]==head[v]) break;
            g(in[head[v]],in[v]+1,x);
            v = par[head[v]];
        }
        g(in[u]+isedge,in[v]+1,x);
    }

    template<class T,class F,class Q,class R>
    T query(int u,int v,const T &e,const F& f,const Q& q,const R& rev,bool isedge=false){
        T l = e,r = e;
        while(true){
            if(in[u]>in[v]){
                swap(u,v); swap(l,r);
            }
            if(head[u]==head[v]) break;
            l = f(q(in[head[v]],in[v]+1),l);
            v = par[head[v]];
        }
        return f(rev(f(q(in[u]+isedge,in[v]+1),l)),r);
    }

    int getin(int v){return in[v];}
};

int main(){
	cin.tie(0);
    ios::sync_with_stdio(false);
    int N,Q;
    cin >> N >> Q;
    vec<ll> A(N);
    for(int i=0;i<N;i++) cin >> A[i];
    vvec<edge> g(N);
    for(int i=0;i<N-1;i++){
        int a,b;
        cin >> a >> b;
        a--; b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    HeavLightDecomposition HLD(N,0,g);
    struct state{
        ll ans,lsum,rsum,sum,len;
    };
    auto op = [&](state L,state R){
        ll ans = max({L.ans,R.ans,L.rsum+R.lsum});
        ll lsum = max(L.lsum,L.sum+R.lsum);
        ll rsum = max(R.rsum,R.sum+L.rsum);
        ll sum = L.sum+R.sum;
        ll len = L.len+R.len;
        return (state) {ans,lsum,rsum,sum,len};
    };
    auto homo = [&](state S,ll x){
        ll ans = (x>0? x*S.len:x);
        ll lsum = (x>0? x*S.len:x);
        ll rsum = (x>0? x*S.len:x);
        ll sum = x*S.len;
        ll len = S.len;
        return (state) {ans,lsum,rsum,sum,len};
    };
    const ll inf = -1e18;
    auto comp = [&](ll x,ll y){return (y!=inf? y:x);};
    state e = (state){inf,inf,inf,0,0};
    LazySegmentTree<state,ll,decltype(op),decltype(homo),decltype(comp)>
    seg(N,op,homo,comp,(state){inf,inf,inf,0,0},inf);
    for(int i=0;i<N;i++){
        seg.set(HLD.getin(i),(state){A[i],A[i],A[i],A[i],1});
    }
    seg.build();

    auto update = [&](int l,int r,ll x){
        seg.update(l,r,x);
    };

    auto query = [&](int l,int r){
        return seg.query(l,r);
    };

    auto rev = [&](state L){
        return (state){L.ans,L.rsum,L.lsum,L.sum,L.len};
    };
    for(int _=0;_<Q;_++){
        int t;
        cin >> t;
        if(t==1){
            int a,b; ll x;
            cin >> a >> b >> x;
            a--; b--;
            HLD.update(a,b,x,update);
        }else{
            int a,b,c;
            cin >> a >> b >> c;
            a--; b--;
            state res = HLD.query(a,b,e,op,query,rev);
            cout << res.ans << endl;
        }
    }
}