#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<cctype>
#include<cmath>
#include<cstdlib>
#include<queue>
#include<ctime>
#include<vector>
#include<set>
#include<map>
#include<stack>
#include<climits>
using namespace std;
const int inf = INT_MAX;
int n,m,f[40010],mf[40010],pre[40010],from[40010];
int head[40010],nxt[40010],to[40010];
int cost[40010],ath[40010],fr[40010],cnt;
int d[40010];
bool iq[40010];
int s,t,Ans;
int q[400100],fi,la;
inline void add(int x,int y,int z,int c){nxt[++cnt]=head[x];head[x]=cnt;to[cnt]=y;f[cnt]=z;cost[cnt]=c;fr[cnt]=x;nxt[++cnt]=head[y];head[y]=cnt;to[cnt]=x;f[cnt]=0;cost[cnt]=-c;fr[cnt]=y;ath[cnt]=cnt-1;ath[cnt-1]=cnt;
}
inline void go(){register int i;while(1){for(i=s;i<=t;i+=4)d[i]=d[i+1]=d[i+2]=d[i+3]=inf;fi=la=100001;q[fi]=s;d[s]=0;iq[s]=1;int flow=inf;while(fi<=la){int x=q[fi];fi++;iq[x]=0;if(d[x]>=inf)continue;for(i=head[x];i;i=nxt[i]){if(f[i]&&d[to[i]]>d[x]+cost[i]){d[to[i]]=d[x]+cost[i];pre[to[i]]=i;flow=min(flow,f[i]);if(!iq[to[i]]){if(d[to[i]]>d[q[fi]])q[++la]=to[i];else q[--fi]=to[i];iq[to[i]]=1;}}} }if(d[t]>=inf)return;int wh=pre[t];while(wh){f[wh]-=flow;f[ath[wh]]+=flow;Ans+=flow*cost[wh];wh=pre[fr[wh]];}}
}
inline int ra(){int x=0,f=1;char s=getchar();while(!isdigit(s)){if(s=='-')f=-1;s=getchar();}while(isdigit(s))x=(x<<3)+(x<<1)+(s-'0'),s=getchar();return x*f;
}
int main(){register int i;n=ra(),m=ra();s=0,t=n+2;for(i=1;i<=n;++i){int x;x=ra();add(i,i+1,inf-x,0);}add(s,1,inf,0),add(n+1,n+2,inf,0);for(i=1;i<=m;++i){int x,y,z;x=ra(),y=ra(),z=ra();add(x,y+1,inf,z);}go();printf("%d\n",Ans);return 0;
}