#pragma comment(linker, "/STACK:216000000")
#include <iostream>
#include <cstdio>
#include <fstream>
#include <vector>
#include <string>
#include <queue>
#include <map>
#include <algorithm>
#include <numeric>
#include <set>
#include <bitset>
#include <sstream>
#include <array>
#include <iomanip>

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int uint;
const ll MAX = numeric_limits<ll>::max();
const ll MIN = numeric_limits<ll>::min();
const double PI = 3.1415926535;
const ll MOD = 1000000007;

template<class T>
ostream& operator<<(ostream& out, vector<T>& v) {
	for (int i = 0; i < v.size(); ++i)
		out << v[i] << " ";
	out << endl;
	return out;
}

template<class T>
istream& operator>>(istream& in, vector<T>& v) {
	for (int i = 0; i < v.size(); ++i)
		in >> v[i];
	return in;
}

template<class T>
T lexical_cast(string& s) {
	stringstream ss(s);
	T t;
	ss >> t;
	return t;
}

ll gcd(ll a, ll b) {
	if (b == 0)
		return a;
	return gcd(b, a % b);
}

ll ceil(ll a, ll b) {
	if (a % b)
		return a / b + 1;
	return a / b;
}

int main() {
	ios_base::sync_with_stdio(false);
#ifdef DEBUG
	ifstream cin{ "input.txt" };
	ofstream cout{ "output.txt" };
#endif
	int n;
	cin >> n;
	vector<int> m(n);
	cin >> m;
	vector<vector<ll>> A(n + 1, vector<ll>(n + 1, 1));
	for (int k = 1; k <= n; ++k) {
		for (int j = 1; j <= k; ++j) {
			A[k][j] = (A[k][j - 1] * (k - j + 1)) % MOD;
		}
	}
	vector<vector<ll>> d(n + 1, vector<ll>(n + 1, -1));
	for (int i = 1; i <= n && (i == 1 || m[i - 2] < m[i - 1]); ++i) {
		d[i][i] = 1;
	}
	for (int i = 1; i <= n; ++i) { //   i
		for (int k = 1; k <= i; ++k) { //  
			if (d[i][k] == -1)
				continue;
			for (int j = 1; j <= k && i + j <= n && (j == 1 || m[i + j - 1] > m[i + j - 2]); ++j) {
				if (d[i + j][j] == -1)
					d[i + j][j] = 0;
				d[i + j][j] = (d[i + j][j] + d[i][k] * A[k][j]) % MOD;
			}
		}
	}
	ll ans = 0;
	for (int i = 1; i <= n; ++i) {
		if (d[n][i] != -1) {
			ans = (ans + d[n][i]) % MOD;
		}
	}
	cout << ans;

}