#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAXN = 8010,INF = 1e9;
template<typename T>void tomin(T& x,T y){x = min(x,y);}
template<typename T>void tomax(T& x,T y){x = max(x,y);}
//
int n,m,c[MAXN],sum[MAXN][MAXN],all[MAXN],arr[MAXN][MAXN],len[MAXN];

int f[2][MAXN][MAXN],g[2],ans;

int main(){
    cin>>n; for(int i=1;i<=n;i++)cin>>c[i],arr[i][++len[i]] = 0;
    cin>>m; for(int i=1,p;i<=m;i++){
        cin>>p;
        sum[p][i]++; all[p]++;
        if(i<m)arr[p][++len[p]] = arr[p+1][++len[p+1]] = i;
    } 
    for(int i=1;i<n;i++)for(int j=1;j<=m;j++)sum[i][j] += sum[i][j-1];
    for(int i=1;i<=n;i++)arr[i][++len[i]] = m; arr[0][++len[0]] = m;

    for(int i=0;i<2;i++)for(int j=0;j<m;j++)for(int k=0;k<=m;k++)f[i][j][k] = -INF; g[0] = g[1] = -INF;
    g[0] = 0;
    for(int i=1;i<=n;i++){
        int p = (i-1)&1,q = i&1; 
        //f -> f
        for(int id=1;id<len[i-1];id++){
            int x = arr[i-1][id];
            for(int S=0;S<=m;S++){
                int& w = f[p][x][S]; if(w == -INF)continue;
                for(int jd=1;jd<len[i];jd++){
                    int y = arr[i][jd];
                    int nw = w + all[i-1] - sum[i-1][max(x,y)];
                    int vx = sum[i-1][y] + sum[i][y] - c[i];
                    int vy = sum[i][y] - c[i]; if(x < y)vy += sum[i-1][y] - sum[i-1][x];
                    int nk = min(vx,S + vy); 
                    if(nk < 0)continue;
                    tomax(f[q][y][nk],nw);
                }
            }
        }
        //f -> g
        for(int id=1;id<len[i-1];id++){
            int j = arr[i-1][id];
            for(int k=0;k<=m;k++){
                int& w = f[p][j][k]; if(w == -INF)continue;
                tomax(g[q],w);
                w = -INF;
            }
        }
        //g -> f
        for(int id=1;id<len[i];id++){
            int j = arr[i][id],vx = sum[i-1][j] + sum[i][j] - c[i];
            if(vx < 0)continue;
            tomax(f[q][j][vx],g[p]);
        }
        //g -> g
        tomax(g[q],g[p]);
        g[p] = -INF;
    }
    tomax(ans,g[n&1]); for(int j=0;j<m;j++)for(int k=0;k<=m;k++)tomax(ans,f[n&1][j][k]);
    cout<<ans<<endl;
    return 0;
}