#include<bits/stdc++.h>
#define int long long
using namespace std;
int n,m,s[300001],fa[300001];
vector<int> ans;
int gf(int x){
	if(fa[x]==x) return x;
	return fa[x]=gf(fa[x]);
}
struct sbdcz{
	int u,d;
	bool operator<(const sbdcz &jjrt)const{
		return jjrt.d<d;
	}
};
priority_queue<sbdcz> q,qn[300001];
struct dcz{
	int x,y,z;
}a[300001];
void update(int x){
	int fx=gf(a[x].x),fy=gf(a[x].y);
	if(fx==fy) return;
	if(s[fx]+s[fy]>=a[x].z){
		q.push({0,x});
		return;
	}
	int o=(a[x].z-s[fx]-s[fy]+1)/2;
	qn[fx].push({x,o-s[fx]});
	qn[fy].push({x,o-s[fy]});
}
signed main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>s[i];
		fa[i]=i;
	}
	for(int i=1;i<=m;i++){
		cin>>a[i].x>>a[i].y>>a[i].z;
		update(i);
	}
	while(q.size()){
		int x=q.top().d;
		q.pop();
		int fx=gf(a[x].x),fy=gf(a[x].y);
		if(fx==fy) continue;
		ans.push_back(x);
		if(qn[fx].size()<qn[fy].size()) swap(fx,fy);
		fa[fy]=fx;
		s[fx]+=s[fy];
		while(qn[fy].size()){
			sbdcz xx=qn[fy].top();
			qn[fy].pop();
			if(xx.d<=s[fx]){
				update(xx.u);
			}
			else{
				qn[fx].push(xx);
			}
		}
		while(qn[fx].size()){
			sbdcz xx=qn[fx].top();
			qn[fx].pop();
			if(xx.d<=s[fx]){
				update(xx.u);
			}
			else{
				qn[fx].push(xx);
				break;
			}
		}
	}
	cout<<ans.size()<<"\n";
	for(auto i:ans){
		cout<<i<<" ";
	}
	return 0;
}