#include <bits/stdc++.h>

using namespace std;

const int N = 1222;
const long long mod = (long long)1e9 + 7;

int n, a[N], b[N];
long long f[N][N], ff[N], rff[N];

long long C[N][N];

long long power(long long a, long long n) {
    if (n == 0) return 1LL;
    if (n % 2 == 0LL) {
        long long x = power(a, n / 2LL);
        return (x * x) % mod;
    } else {
        return (a * power(a, n - 1)) % mod;
    }
}

void CNK(){
    for (int n = 0; n < N; ++n) {
        C[n][0] = C[n][n] = 1;
        for (int k = 1; k < n; ++k)
            C[n][k] = (1LL * C[n - 1][k - 1] + 1LL * C[n - 1][k]) % mod;
    }
    ff[0] = 1LL;
    for (int i = 1; i < N; ++i)
        ff[i] = (ff[i - 1] * i) % mod;
    for (int i = 0; i < N; ++i)
        rff[i] = power(ff[i], mod - 2);
}

int solve(int cntV, int cntN) {
    if (cntV < 0) return 0;
    if (cntN < 0) return 0;
    if (cntN == 0 && cntV  >= 0) return 1;
    long long &res = f[cntV][cntN];
    if (res != -1) return res;
    res = 0;
    int p = n - cntN;
    for (int i = p; i - p + 1 <= cntV && i < n; ++i) {
        if (i == p) {
            (res += 1LL * cntV * solve(1, cntN - 1)) %= mod;
        } else {
            if (a[i - 1] > a[i]) break;
            (res += 1LL * ((C[cntV][i - p + 1] * ff[i - p + 1]) % mod) * solve(i - p + 1, cntN - (i - p + 1))) %= mod;
        }
    }
    return res;
}

int main()
{
    ios_base::sync_with_stdio(false);
//    ifstream cin("input.txt");
    cin >> n;
    CNK();
    for (int i = 0; i < N; ++i)
        for (int j = 0; j < N; ++j)
            f[i][j] = -1;
    long long ans = 0LL;
    for (int i = 0; i < n; ++i) cin >> a[i];
    for (int i = 1; i <= n; ++i) {
        if (i == 1 || (a[i - 2] <= a[i - 1]))
            (ans += solve(i, n - i)) %= mod;
        if (a[i - 2] > a[i - 1]) break;
    }
    cout << ans << endl;
    return 0;
}