#include <bits/stdc++.h>

using namespace std;

const int MAXM = 1210;
const long long mod = 1000000007;

long long F[MAXM][MAXM];
long long S[MAXM];
long long Si[MAXM];
int M[MAXM];

long long mul_inv(long long a, long long b)
{
	long long b0 = b, t, q;
	long long x0 = 0, x1 = 1;
	if (b == 1) return 1;
	while (a > 1) {
		q = a / b;
		t = b, b = a % b, a = t;
		t = x0, x0 = x1 - q * x0, x1 = t;
	}
	if (x1 < 0) x1 += b0;
	return x1;
}

bool isSorted(int m, int k)
{
    for (int i=1;i<k;++i)
        if (M[m+i] < M[m+i-1])
            return false;
    return true;
}

int main(){
    int n;
    cin >> n;
    for(int i = 0; i < n; i++)
       cin >> M[i];
    
    for (int m=n-1;m>=0;--m)
        F[m][1] = 1;
    for (int k=1;k<=n;++k)
        F[n-k][k] = isSorted(n-k,k) ? 1 : 0;
    
    S[0] = 1;
    for (int i=1;i<=n;++i)
        S[i] = S[i-1]*((long long)i)%mod;
    for (int i=0;i<=n;++i)
        Si[i] = mul_inv(S[i], mod);
        
    for (int k=2;k<=n;++k)
    {
        for (int m=n-k-1;m>=0;--m)
        {
            long long Fk = 0;
            if (isSorted(m,k))
            {
                for (int kk=1;kk<=k;++kk)
                {
                    //std::clog << ":: " << k << " " << m << " " << kk << std::endl;
                    if (m+k+kk <= n)
                        Fk = (Fk + F[m+k][kk] * S[k] % mod * Si[k-kk] % mod) % mod;
                }
            }
            F[m][k] = Fk;
        }
    }
    /*
    for (int k=1;k<=n;++k)
    {
        for (int m=0;m<n;++m)
        {
            std::clog << F[m][k] << " ";
        }
        std::clog << std::endl;
    }
    */
    long long result = 0;
    for (int k=1;k<=n;++k)
        result += F[0][k];
    std::cout << result%mod << std::endl;
    return 0;
}