#include<bits/stdc++.h>
using namespace std;
int n,p,x,y,z,a[5000001],ans = INT_MAX;
int main(){
	scanf("%d%d",&n,&p);
	for(int i = 1;i<=n;i++)scanf("%d",&a[i]);
	while(p--){
		int x,y,z;
		scanf("%d%d%d",&x,&y,&z);
		a[x]+=z;
		a[y+1]-=z;
	}
	for(int i = 1;i<=n;i++){
		a[i]+=a[i-1];
		ans = min(ans,a[i]);
	}
	printf("%d",ans);
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main(){
	printf("2");
	return 0;
}