#include<bits/stdc++.h>
using namespace std;
const int N=5000010;
int n,p,x,y,z,ans=220,sum,a[N];
int main()
{
    cin>>n>>p;
    for(int i=1;i<=n;i++) cin>>a[i],a[i]-=a[i-1];
    for(int i=1;i<=p;i++) cin>>x>>y>>z,a[x]+=z,a[y+1]-=z;
    for(int i=1;i<=n;i++) sum+=a[i],ans=min(ans,sum);
    cout<<ans<<endl;
    return 0;
}