#include<bits/stdc++.h>
const int N =5e6+5; 
using namespace std;
int student[N];
int student1[N];
int n,p;
int x,y,z;
int minn=101;
int main(){	
	cin>>n>>p;
	for(int i=1;i<=n;i++){
		cin>>student[i];
	}
	for(int i=1;i<=n;i++){
		student1[i]=student[i]-student[i-1];
//		cout<<student1[i]<<" ";
	}
//	cout<<endl;
	while(p--){
		cin>>x>>y>>z;
		student[x]+=z,student[y+1]-=z;
	}
	for(int i=1;i<=n;i++){
//		cout<<student[i]<<" ";
		student1[i]=student1[i-1]+student[i];	
		minn=min(minn,student1[i]);
	}
	cout<<minn;
	return 0;
}