#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

int n;
const long long P = 1000000007; // our prime number
long long Fact[1300]; // array of factorials mod P
long long C[1300][1300]; //choose array, filled used fillC (pascals method)
long long mem[1300][1300]; // our memoization table for DP
bool good[1300][1300]; // good[i][j] says that elements x_i....x_j in our original array are sorted



//fills C using pascals triangle
long long fillC(int row, int col) {
	if (col == 0 || col == row) {
		C[row][col] = 1;
	}
	else if(C[row][col]==0) {
		C[row][col]= (fillC(row - 1, col - 1) + fillC(row - 1, col))%P;
		
	}

	return C[row][col];
}


//DP function
int tbcnt = 0;
long long f(int i, int k) {

	if (i +k > n) mem[i][k]= 0; //cannot create any more arrays
	else if (good[i][i + k - 1] == 0) mem[i][k] = 0; //cannot divide, not sorted
	else if ( (i+k)  == n) mem[i][k] = 1; //take all the remaning elements in one way

	if (mem[i][k] == -1) {

		long long res = 0;
		for (int j = 1;j <= k;j++) {
			if (i + j > n) break;
			res = (res + (((Fact[j] * C[k][j]) % P)*(f(i + k, j)))%P) % P;
		}

		mem[i][k] = res;

	}


	return mem[i][k];

}





int main() {
	cin >> n;
	vector<int> m(n);
	for (int m_i = 0; m_i < n; m_i++) {
		cin >> m[m_i];
		//m[m_i] = m_i;
	}
	//initialize arrays mem, good and C
	for (int i = 0;i <= n;i++) for (int j = 0;j <= n;j++) {
		mem[i][j] = -1; good[i][j] = 0; C[i][j] = 0;
	}
	//make sure you to fill all C table
	for (int i = 0;i <= n;i++) for (int j = 0;j <= i;j++) fillC(i, j);
	
	//fill Fact table
	Fact[0] = 1;
	for (int i = 1;i <= n;i++) Fact[i] = (i*Fact[i - 1])%P;

	//fill good table
	for (int i = 0;i < n;i++) {
		good[i][i] = 1;
		for (int j = i + 1;j < n;j++) {
			if (m[j] >= m[j - 1]) good[i][j] = 1;
			else break;
		}
	}

	//calculate our answers
	long long res = 0;
	for (int k = 1;k <= n;k++) {
			res = (res + f(0, k)) % P;
	}
	cout << res << endl;;

	


	return 0;
}