#include<bits/stdc++.h>
#define ull unsigned long long
using namespace std;
const int N = 2e5 + 10, D = 18;
vector<int>g1[N],g2[N];
int n;

int sqn, dl[N], dr[N], dfn, l[N], r[N], bel[N], fa[N][D+1], dep1[N];
ull a1[N], a2[N];
ull ans[N], val[N];
void dfs(int x, int f)
{
	dl[x] = ++dfn, fa[x][0] = f, dep1[x] = dep1[f] + 1;
	for(int i=1;i<=D;i++) fa[x][i] = fa[fa[x][i-1]][i-1];
	for(auto j:g1[x]) if(j!=f) val[x] -= val[j], dfs(j,x);
	dr[x] = dfn;
}
int LCA(int x, int y)
{
	if(dep1[x]>dep1[y]) swap(x,y);
	int i;
	for(i=D;i>=0;i--) if(dep1[fa[y][i]]>=dep1[x]) y = fa[y][i];
	if(x==y) return x;
	for(i=D;i>=0;i--) if(fa[x][i]!=fa[y][i]) x = fa[x][i], y = fa[y][i];
	return fa[x][0];
}
void init()
{
	dfs(1,0);
	sqn = (int)sqrt(n);
	int i, j;
	for(i=1;r[i-1]!=n;i++) l[i] = r[i-1] + 1, r[i] = min(l[i]+sqn-1,n);
	sqn = i - 1;
	for(i=1;i<=sqn;i++) for(j=l[i];j<=r[i];j++) bel[j] = i;
}
void add(int a, ull x)
{
	a = dl[a];
	int p = bel[a], i;
	for(i=a;i<=r[p];i++) a1[i] += x;
	for(i=p+1;i<=sqn;i++) a2[i] += x;
}
ull ask(int x)
{
	return a1[dr[x]] + a2[bel[dr[x]]] - a1[dl[x]-1] - a2[bel[dl[x]-1]];
}
struct qq{int id,k,x;}qu[N*4],fd[N*4];int cq;
struct op{int x,id;ull y;}ad[N*8];int co;
void ins(int x, int id, ull y){add(x,y),ad[++co]={x,id,y};}

int cnt[N];
int dep[N], p[N], is[N], fa2[N], up[N], faa[N][D+1];
int LCA2(int x, int y)
{
	int i;
	if(dep[x]>dep[y]) swap(x,y);
	for(i=D;i>=0;i--) if(dep[faa[y][i]]>=dep[x]) y = faa[y][i];
	if(x==y) return x;
	for(i=D;i>=0;i--) if(faa[x][i]!=faa[y][i]) x = faa[x][i], y = faa[y][i];
	return faa[x][0];
}
void dfs2(int x, int f)
{
	dep[x] = dep[f] + 1, fa2[x] = faa[x][0] = f;
	for(int i=1;i<=D;i++) faa[x][i] = faa[faa[x][i-1]][i-1];
	for(auto j:g2[x]) if(j!=f) dfs2(j,x);
}
void init2()
{
	int sqn = (int)sqrt(n);
	sqn *= 2;
	dfs2(1,0);
	int i;
	for(i=1;i<=n;i++) p[i] = i;
	sort(&p[1],&p[n]+1,[](int a,int b){return dep[a]>dep[b];});
	for(i=n-1;i>=1;i--)
	{
		int x = p[i], y = fa2[x], z = sqn;
		while(y>1&&z)
		{
			if(is[y]) break;
			y = fa2[y], z--;
		}
		if(!z) is[y] = 1;
	}
	is[1] = 1;
	for(i=2;i<=n;i++) if(is[i])
	{
		int x = fa2[i];
		while(!is[x]) x = fa2[x];
		up[i] = x;
	}
//	int c = 0;
//	for(i=1;i<=n;i++) c += is[i];
//	assert(c<=n/sqn+10);
}

void dfsp(int x, int f)
{
	for(auto j:g1[x]) if(j!=f) cnt[j] += cnt[x], dfsp(j,x);
}

int ww[N];

int main()
{
	int m, i, a, b;
	scanf("%d%d", &n, &m);
	for(i=1;i<=n;i++) scanf("%llu", &val[i]);
	for(i=1;i<n;i++) scanf("%d%d", &a, &b), g1[a].emplace_back(b), g1[b].emplace_back(a);
	for(i=1;i<n;i++) scanf("%d%d", &a, &b), g2[a].emplace_back(b), g2[b].emplace_back(a);
	init(), init2();
	for(i=1;i<=n;i++)
	{
		ins(i,0,val[i]);
//		if(i>1) ins(fa[i][0],0,-val[i]);
	}
	for(i=1;i<=m;i++)
	{
		int x, y, xx, yy, l;
		ull k;
		scanf("%d%d%llu", &x, &y, &k), xx = x, yy = y;
		l = LCA(x,y), ins(x,i,k), ins(y,i,k), ins(l,i,-k);
		if(l!=1) ins(fa[l][0],i,-k);
		l = LCA2(x,y);
		while(!is[x]&&x!=l) ans[i] += ask(x), x = fa2[x];
		while(!is[y]&&y!=l) ans[i] += ask(y), y = fa2[y];
		int x1 = x, y1 = y;
		while(dep[up[x]]>=dep[l]) x = up[x];
		while(dep[up[y]]>=dep[l]) y = up[y];
		if(x!=x1) qu[++cq] = {i,1,x1}, qu[++cq] = {i,-1,x};
		if(y!=y1) qu[++cq] = {i,1,y1}, qu[++cq] = {i,-1,y};
		if(dep[x]>dep[y]) swap(x,y);
		while(dep[x]<dep[y]) ans[i] += ask(y), y = fa2[y];
		while(x!=y) ans[i] += ask(x) + ask(y), x = fa2[x], y = fa2[y];
		ans[i] += ask(l);
	}
	for(i=1;i<=cq;i++) ww[qu[i].x]++;
	for(i=1;i<=n;i++) ww[i] += ww[i-1];
	for(i=cq;i>=1;i--) fd[ww[qu[i].x]--] = qu[i];
	for(i=1;i<=cq;i++) qu[i] = fd[i];
	for(i=1;i<cq;i++) assert(qu[i].x<qu[i+1].x||(qu[i].x==qu[i+1].x&&qu[i].id<=qu[i+1].id));
	int aaa = 0, l, r;
	for(i=1;i<=cq;i=r+1)
	{
		l = i, r = i;
		int x, j;
		ull res = 0;
		while(r<=cq&&qu[r].x==qu[l].x) r++;
		r--, x = qu[l].x;
//		if(!is[x]) cout<<"sfdahsfda\n";
		aaa++;
//		continue;
		for(i=1;i<=n;i++) cnt[i] = 0;
		for(i=x;i;i=fa2[i]) cnt[i] = 1;
		dfsp(1,0);
		for(i=l,j=1;i<=r;i++)
		{
			while(j<=co&&ad[j].id<=qu[i].id) res += ad[j].y * cnt[ad[j].x], j++;
			ans[qu[i].id] += res * qu[i].k;
		}
	}
	assert(aaa<=n/sqn+10);
	for(i=1;i<=m;i++) printf("%llu\n", ans[i]);
	return 0;
}