#include <bits/stdc++.h>

using namespace std;

int main(){
    int n;
    cin >> n;
    vector<int> m(n);
    for(int m_i = 0; m_i < n; m_i++){
       cin >> m[m_i];
    }
    vector<vector<int>> f(n + 1, vector<int>(n + 1, 0));
    vector<vector<long long>> A(1201, vector<long long>(1201, 0));
    f[0][1] = 1;
    for (int i = 1; i < n && m[i] >= m[i - 1]; i++) {
        f[i][i + 1] = 1;
    }
    const int mod = 1e9 + 7;
    for (int i = 1; i <= 1200; i++) {
        A[i][1] = i;
        for (int j = 2; j <= i; j++) {
            A[i][j] = A[i][j - 1] * (long long)(i - j + 1) % (long long)mod;
        }
    }
    for (int i = 0; i < n - 1; i++)
        for (int j = 1; j <= i + 1; j++)
        if (f[i][j] > 0) {
        for (int k = i + 1; k < n && k <= i + j && (k == i + 1 || m[k] >= m[k - 1]); k++) {
            f[k][k - i] += (long long)f[i][j] * A[j][k - i] % (long long) mod;
            if (f[k][k - i] >= mod) {
                f[k][k - i] -= mod;
            }
        }
    }
    int ans = 0;
    for (int i = 1; i <= n; i++) {
        ans += f[n - 1][i];
        if (ans >= mod) {
            ans -= mod;
        }
    }
    cout << ans << endl;
    // your code goes here
    return 0;
}