#include<algorithm>
#include<cstdio>
#include<cstring>
using namespace std;
const int N=5e6+5;
int a[N],d[N];
int main(){
	memset(d,0,sizeof(d));
	int n,m;
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;++i){
		scanf("%d",&a[i]);
	}
	int h=-1;
	while(m--){
		int x,y,z;
		scanf("%d%d%d",&x,&y,&z);
		d[x]+=z;
		d[y+1]-=z;
		if(y>h)h=y;
	}
	for(int i=2;i<=h;++i){
		d[i]+=d[i-1];
	}
	int ans=1<<30;
	for(int i=1;i<=n;++i){
		if(a[i]+d[i]<ans)ans=a[i]+d[i];
	} 
	printf("%d\n",ans);
	return 0;
}