#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1201, mod = 1e9 + 7;
int n, c[N][N], last[N], a[N], ans;
ll d[N][N], fact[N];
int main()
{
	cin >> n;
    //n = 1200;
	for(int i = 0;i <= n; ++ i){
		if(i)fact[i] = (fact[i - 1] * i) % mod;
		else fact[i] = 1;
		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];
			c[i][j] %= mod;
		}
	}
	last[0] = 1;
	for(int i = 1;i <= n; ++ i){
		cin >> a[i];
//		a[i] = ((i % 2) ^ 1) + 1;
		last[i] = last[i - 1];
		if(a[i] < a[i - 1])last[i] = i;
	}
	for(int i = 1;i <= n; ++ i)d[0][i] = 1;
	for(int i = 1;i <= n; ++ i){
		if(last[i] == 1)d[i][i] = 1;
		for(int j = 1;j < i && i - last[i] >= j - 1; ++ j){
			for(int k = j;k <= i - j; ++ k){
				d[i][j] += (((d[i - j][k] * c[k][j]) % mod) * fact[j]) % mod;
				d[i][j] %= mod;
			}
		}
	}
	for(int i = 1;i <= n; ++ i){
		ans += d[n][i];
		ans %= mod;
	}
	cout << ans;
	return 0;
}