#include <bits/stdc++.h>
using namespace std;
int a[10000005],b[10000005];
int n,p,l,r,c;

int main(){
	cin>>n>>p;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		b[i]=a[i]-a[i-1];
	}
	for(int i=0;i<p;i++){
		cin>>l>>r>>c;
		b[l]+=c;b[r+1]-=c;
	}
	for(int i=1;i<=n;i++){
		a[i]=a[i-1]+b[i];
	}
	int min=10000000000;
	for(int i=1;i<=n;i++){
		if(min>a[i])min=a[i];
	}
	cout<<min;
}