#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
const int maxn=10205;
const int maxm=1e5+10;

inline int read(){
    int x=0,w=1;char c=getchar();
    while(c<'0'||c>'9'){if(c=='-')w=-1;c=getchar();}
    while(c<='9'&&c>='0'){x=(x<<3)+(x<<1)+c-'0';c=getchar();}
    return x*w;
}

int n,m;
int a[105],id_a[1005];
int d[105][105],id[105][105];
int sum;
bool vis[1005];
int S,T,tot;

struct Graph{
    struct edge{
        int to,nxt,lim;
    }e[maxm<<1];
    int head[maxn],cnt=1;
    inline void add_edge(int u,int v,int w){
        e[++cnt].to=v,e[cnt].nxt=head[u],e[cnt].lim=w,head[u]=cnt;
        e[++cnt].to=u,e[cnt].nxt=head[v],e[cnt].lim=0,head[v]=cnt;
    }
    int cur[maxn],dis[maxn];
    int dfs(int u,int rest){
        if(u==T) return rest;
        int flow=0;
        for(int i=cur[u];i&&rest;i=e[i].nxt){
            cur[u]=i;
            int v=e[i].to,C=min(rest,e[i].lim);
            if(dis[u]+1==dis[v]&&C){
                int k=dfs(v,C);
                flow+=k,rest-=k;
                e[i].lim-=k,e[i^1].lim+=k;
            }
        }
        if(!flow) dis[u]=-1;
        return flow;
    }
    inline int max_flow(){
        int flow=0;
        while(1){
            queue<int> q;
            memcpy(cur,head,sizeof(head));
            memset(dis,-1,sizeof(dis));
            dis[S]=0;
            q.push(S);
            while(!q.empty()){
                int u=q.front();
                q.pop();
                for(int i=head[u];i;i=e[i].nxt){
                    int v=e[i].to;
                    if(dis[v]==-1&&e[i].lim){
                        dis[v]=dis[u]+1;
                        q.push(v);
                    } 
                }
            }
            if(dis[T]==-1) return flow;
            flow+=dfs(S,1e9);
        }
    }
}G;

int main(){
    n=read(),m=read();
    S=1,T=2,tot=2;
    for(int i=1;i<=n;++i){
        a[i]=read();
        if(!vis[a[i]]){
            vis[a[i]]=1;
            id_a[a[i]]=++tot;
            G.add_edge(id_a[a[i]],T,m*a[i]*a[i]);
        }
    }
    for(int i=1;i<=n;++i){
        for(int j=i;j<=n;++j){
            d[i][j]=read();
            id[i][j]=++tot;
        }
    }
    for(int i=1;i<=n;++i){
        for(int j=i;j<=n;++j){
            if(i==j) d[i][j]-=a[i];
            if(d[i][j]>0){
                G.add_edge(S,id[i][j],d[i][j]);
                sum+=d[i][j];
            }
            else G.add_edge(id[i][j],T,-d[i][j]);
            if(i==j) G.add_edge(id[i][j],id_a[a[i]],1e9);
            else{
                G.add_edge(id[i][j],id[i+1][j],1e9);
                G.add_edge(id[i][j],id[i][j-1],1e9);
            }
        }
    }
    printf("%d\n",sum-G.max_flow());
    return 0;
}