#include <iostream>
#include <cstdio>
#include <string>
#include <cassert>
#include <cstdlib>
#include <vector>
#include <algorithm>
#include <set>
#include <map>
#include <bitset>
#include <ctime>
#include <cstdlib>
#include <fstream>
#include <iomanip>
#include <sstream>
#include <numeric>
#include <unordered_map>
#include <unordered_set>

using namespace std;

#define sz(a) (int)(a.size())
#define int long long

int p[1210][1210];
int n;
int b[1210];
int a[1210];
const int MOD = 1e9 + 7;
int dp[1210][1210];
int C[1210][1210];
int F[1210];

signed main()
{
	ios_base::sync_with_stdio(0);
	cin >> n;
	int m = 0;
	for (int i = 1; i <= n; ++i)
		cin >> a[i];
	for (int i = 2; i <= n; ++i)
	{
		if (a[i] < a[i - 1])
		{
			b[i] = 1;
		}
	}
	F[0] = 1;
	for (int i = 1; i <= n; ++i)
	{
		F[i] = F[i - 1] * i % MOD;
		C[i][0] = 1;
		C[i][i] = 1;
		for (int j = 1; j < i; ++j)
			C[i][j] = (C[i - 1][j - 1] + C[i - 1][j]) % MOD;
	}
	int ans = 0;
	for (int i = 1; i <= n; ++i)
	{
		if (b[i])
			break;
		dp[i][i] = 1;
	}
	for (int i = 2; i <= n; ++i)
	{
		for (int j = 1; j <= i; ++j)
		{
			int ok = 1;
			for (int k = i; k > i - j + 1; --k)
				if (b[k])
					ok = 0;
			if (!ok)
				break;
			for (int k = j; k <= i; ++k)
				dp[i][j] = (dp[i][j] + (dp[i - j][k] * C[k][j]) % MOD * F[j]) % MOD;
		}
	}
	for (int i = 1; i <= n; ++i)
		ans = (ans + dp[n][i]) % MOD;
	cout << ans;
	return 0;
}