#include<bits/stdc++.h>

using namespace std;

const int n_ = 1201;
typedef long long ll;
int n;
ll arr[n_];
ll memo[n_][n_];
ll mod = 1e9 + 7;

ll comb[n_][n_]; // Initialize it with -1
ll fact [n_];
ll nCr(int n, int k)		// O(n * k)
		{
	if (n < k)
		return 0;
	if (k == 0 || k == n)//may add k == 1 as a base case for fast calculations
		return 1;
	if (comb[n][k] != -1)
		return comb[n][k];
	if (n - k < k)
		return comb[n][k] = nCr(n, n - k);		//reduce k to n - k
	return comb[n][k] = (nCr(n - 1, k - 1) + nCr(n - 1, k)) % mod;
}

ll fac (int num) {
	if (fact[num] != -1) return fact[num];
	if (num == 0 || num == 1) return fact[num] = 1;

	return fact[num] = num * fac(num - 1) % mod;
}
ll dp (int height, int idx) {
	if (idx == n) return 1;

	ll &ret = memo[height][idx];
	if (ret != -1) return ret;

	ret = (height * dp(1, idx + 1)) % mod;
	for (int i = idx + 1; i < n; i++) {
		if (arr[i] < arr[i - 1] || i - idx + 1 > height) break;
		ll ansHere = (nCr(height, i - idx + 1) * dp(i - idx + 1, i + 1) % mod) * fac(i - idx + 1) % mod;
		ret = (ret + ansHere) % mod;
	}

	return ret;
}
int main () {
	ios_base::sync_with_stdio(0); cin.tie(0);

	cin >> n;
	for (int i = 0; i < n; i++)
		cin >> arr[i];

	memset (memo, -1, sizeof memo);
	memset(comb, -1, sizeof comb);
	memset(fact, -1, sizeof fact);

	ll res = dp(1,1);
	for (int i = 1; i < n; i++) {
		if (arr[i] < arr[i - 1]) break;
		else res = (res + dp(i + 1, i + 1)) % mod;
	}
	cout << res << "\n";
}