P2367

#include<bits/stdc++.h>
using namespace std;
int n,m,x,y,z,minn=1e9,a[500005],s[500005];
int main()
{
	cin>>n>>m;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i];
		s[i]=a[i]-a[i-1];
	}
	while(m--)
	{
		cin>>x>>y>>z;
		s[x]+=z;
		s[y+1]-=z;
	}
	for(int i=1;i<=n;i++)
	{
		a[i]=a[i-1]+s[i];
		minn=min(minn,a[i]);
	}
	cout<<minn;
	return 0;
}