#include <bits/stdc++.h>

using namespace std;

// struct CLOCK{
//     int ST;
//     CLOCK() {ST = clock();}
//     ~CLOCK() {cerr << "Time : " << clock() - ST << endl;}
// };
// CLOCK ACOIPP;

const int N = 5015;

int n, m, q, k, w[N], pre[N];
int res;

template <const int N, const int M>
struct SSP{
    int s, t;
    struct Edge{
        int ne, en, c, w;
    }e[M];
    int la[N], idx = 1;
    int dis[N], pre[N], vis[N], q[N], hh, tt;
    int MinCost;

    inline void AddEdge(int a, int b, int c, int d)
    {
        e[ ++ idx] = {la[a], b, c, d};
        la[a] = idx;
    }
    inline void Add(int a, int b, int c, int d)
    {
        // printf("#%d %d %d %d\n", a, b, c, d);
        AddEdge(a, b, c, d);
        AddEdge(b, a, 0, -d);
    }
    inline bool SPFA()
    {
        memset(dis, -0x3f, sizeof dis), dis[s] = 0;
        hh = 0, tt = 1, q[0] = s;
        int CNT = 0;
        while(hh != tt)
        {
            int u = q[hh ++ ];
            (hh == N) && (hh = 0);
            vis[u] = 0;
            for(int i = la[u]; i; i = e[i].ne)
            {
                CNT ++ ;
                int v = e[i].en;
                if(e[i].c && dis[v] < dis[u] + e[i].w)
                {
                    dis[v] = dis[u] + e[i].w;
                    pre[v] = i;
                    if(!vis[v])
                    {
                        q[tt ++ ] = v;
                        (tt == N) && (tt = 0);
                        vis[v] = 1;
                    }
                }
            }
            if(CNT >= 10000000) break ;
        }

        if(dis[t] <= 0) return 0;
        int c = 1e9;
        for(int u = t; u != s; u = e[pre[u] ^ 1].en)
            c = min(c, e[pre[u]].c);
        MinCost += c * dis[t];
        for(int u = t; u != s; u = e[pre[u] ^ 1].en)
        {
            e[pre[u]].c -= c;
            e[pre[u] ^ 1].c += c;
        }
        return 1;
    }
    inline int Work()
    {
        while(SPFA()) ;
        return MinCost;
    }
};
SSP<N, N * 4> G;

int main()
{
    // freopen("db.in", "r", stdin);
    // freopen("db.out", "w", stdout);

    scanf("%d%d%d", &n, &m, &q), m -- ;
    G.s = 0, G.t = q + 1;
    G.Add(0, 1, m, 0);
    for(int i = 1; i <= n; i ++ ) scanf("%d", &w[i]);
    for(int i = 1; i <= q; i ++ )
    {
        scanf("%d", &k);
        if(pre[k])
        {
            if(pre[k] != i - 1)
            {
                res += w[k];
                G.Add(pre[k] + 1, i, 1, w[k]);
            }
        }
        else res += w[k];
        pre[k] = i;
        G.Add(i, i + 1, m, 0);
    }
    res -= G.Work();
    printf("%d\n", res);
    return 0;
}