#include<bits/stdc++.h>
using namespace std;
//#define int long long
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef double db;
#define F(i, a, b) for(int i = a; i <= (b); ++i)
#define F2(i, a, b) for(int i = a; i < (b); ++i)
#define dF(i, a, b) for(int i = a; i >= (b); --i)
template<typename T> void debug(string s, T x) {cerr << "[" << s << "] = [" << x << "]\n";}
template<typename T, typename... Args> void debug(string s, T x, Args... args) {for (int i = 0, b = 0; i < (int)s.size(); i++) if (s[i] == '(' || s[i] == '{') b++;else if (s[i] == ')' || s[i] == '}') b--;else if (s[i] == ',' && b == 0) {cerr << "[" << s.substr(0, i) << "] = [" << x << "] | ";debug(s.substr(s.find_first_not_of(' ', i + 1)), args...);break;}}
#ifdef ONLINE_JUDGE
#define Debug(...)
#else
#define Debug(...) debug(#__VA_ARGS__, __VA_ARGS__)
#endif
#define pb push_back
#define fi first
#define se second
#define Mry fprintf(stderr, "%.3lf MB\n", (&Med - &Mbe) / 1048576.0)
#define Try cerr << 1e3 * clock() / CLOCKS_PER_SEC << " ms\n";
typedef long long ll;
// namespace Fread {const int SIZE = 1 << 17; char buf[SIZE], *S, *T; inline char getchar() {if (S == T) {T = (S = buf) + fread(buf, 1, SIZE, stdin); if (S == T) return '\n';} return *S++;}}
// namespace Fwrite {const int SIZE = 1 << 17; char buf[SIZE], *S = buf, *T = buf + SIZE; inline void flush() {fwrite(buf, 1, S - buf, stdout), S = buf;} inline void putchar(char c) {*S++ = c;if (S == T) flush();} struct NTR {~NTR() {flush();}} ztr;}
// #ifdef ONLINE_JUDGE
// #define getchar Fread::getchar
// #define putchar Fwrite::putchar
// #endif
inline int ri() {
    int x = 0;
    bool t = 0;
    char c = getchar();
    while (c < '0' || c > '9') t |= c == '-', c = getchar();
    while (c >= '0' && c <= '9') x = (x << 3) + (x << 1) + (c ^ 48), c = getchar();
    return t ? -x : x;
}
inline void wi(int x) {
    if (x < 0) {
        putchar('-'), x = -x;
    }
    if (x > 9) wi(x / 10);
    putchar(x % 10 + 48);
}
inline void wi(int x, char s) {
    wi(x), putchar(s);
}
bool Mbe;
const int mod = 998244353;
const int inf = 0x3f3f3f3f;
const ll infll = 0x3f3f3f3f3f3f3f3f;
const int _ = 2e5 + 5;

int n, L, ans, C[_], X[_], S[_];

vi p[_];

vector<vi> dp[_];

bool Med;
signed main() {
    // Mry;
    L = ri();
    F(i, 1, L) C[i] = ri(), p[i].pb(0);
    n = ri();
    F(i, 1, n) {
        X[i] = ri(), p[X[i]].pb(i), p[X[i] + 1].pb(i);
    }
    F(i, 1, L) {
        C[i] = min(C[i], (int)(p[i].size()) - 1);
    }
    F(i, 1, L) {
        dp[i].resize(p[i].size());
        F(j, C[i], (int)p[i].size() - 1) {
            dp[i][j].resize((int)p[i].size() - C[i], -inf);
        }
    }
    F(i, C[1], (int)p[1].size() - 1) dp[1][i][i - C[1]] = 0;
    F(i, 2, L) {
        F(j, 1, n) S[j] = S[j - 1] + (X[j] == i - 1);
        F(j, C[i - 1], (int)p[i - 1].size() - 1) {
            F(k, 0, (int)p[i - 1].size() - 1 - C[i - 1]) if(dp[i - 1][j][k] != -inf) {
                F(t, C[i], (int)p[i].size() - 1) {
                    int d;
                    if(j + 1 == (int)p[i - 1].size() || t + 1 == p[i].size()) d = t - C[i];
                    else {
                        d = min(k - S[min(p[i - 1][j], p[i][t])], 0) + t - C[i];
                    }
                    if(d >= 0) {
                        dp[i][t][d] = max(dp[i][t][d], dp[i - 1][j][k] + S[n] - S[max(p[i - 1][j], p[i][t])]);
                    }
                }
            }
        }
    }
    ans = 0;
    F(i, C[L], (int)p[L].size() - 1) {
        F(j, 0, (int)p[L].size() - 1 - C[L]) if(dp[L][i][j] != -inf) {
            ans = max(ans, dp[L][i][j]);
        }
    }
    cout <<ans << '\n';
    // Try;
    return 0;
}