#include<bits/stdc++.h>
using namespace std;
int n,m;
int d[1000005],s[1000005],t[1000005];
int b[1000005];
int check(int l,int k){
	for(int i=l;i<=k;i++){
		for(s[i];s[i]<=t[i];s[i]++){
			b[s[i]]-=d[i];
			if(b[s[i]]<0)return i;
		}
	}
	return 0;
}
int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++)cin>>b[i];
	for(int i=1;i<=m;i++)cin>>d[i]>>s[i]>>t[i];
	int low=1,high=m;
//	while(1){
		while(low<high){
			int mid=(low+high)/2;
			if(check(low,mid)){
				cout<<"-1"<<endl<<check(low,mid);
				return 0;
			}
			if(!check(low,mid)){
				low=mid+1;
			}
		}
//	}
	cout<<"0";
	return 0;
}