#define _CRT_SECURE_NO_WARNINGS

#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <cstdio>

//#include <cstdint>
//#include <cstdlib>
#include <cassert>
//#include <cctype>
#include <climits>
#include <functional>
#include <numeric>
#include <algorithm>
#include <cmath>
#include <ctime>

#include <string>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <list>
#include <deque>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <array>

using namespace std;

#define forn(i, n) for(int i = 0; i < int(n); i++)
#define forn1(i, n) for(int i = 1; i <= int(n); i++)
#define sz(a) int((a).size())
#define all(a) (a).begin(), (a).end()
#define mp make_pair
#define pb push_back
#define x first
#define y second

typedef long long li;
typedef long double ld;
typedef pair<int, int> pt;

const int INF = int(1e9);
const li INF64 = li(1e18);
const ld PI = acosl(ld(-1));
const ld EPS = 1e-9;

template <typename T> inline T sqr(const T& x) {
	return x * x;
}

template <typename T> inline T abs(const T& x) {
	return x > 0 ? x : -x;
}

inline bool inside(int x, int y, int n, int m) {
	return x >= 1 && x <= n && y >= 1 && y <= m;
}

inline int rnd() {
	return abs(rand() ^ (rand() << 15));
}

inline int rnd(int n) {
	assert(n > 0);
	return rnd() % n;
}

inline int rnd(int lf, int rg) {
	return lf + rnd(rg - lf + 1);
}

inline li rndLL() {
	return rnd() * 1LL * rnd() + rnd();
}

const int dx[4] = { -1, 0, +1, 0 };
const int dy[4] = { 0, +1, 0, -1 };

const int dx8[8] = { -1, -1, 0, +1, +1, +1, 0, -1 };
const int dy8[8] = { 0, +1, +1, +1, 0, -1, -1, -1 };

const int N = int(1222);

int n, a[N];

inline void gen() {
	return;
}

inline bool read() {
	if (!(cin >> n)) return false;
	forn1(i, n) assert(cin >> a[i]);
	return true;
}

const int MOD = INF + 7;

inline int mul(int a, int b) {
	li res = a * 1LL * b;
	if (res >= MOD) res %= MOD;
	return int(res);
}

inline int sum(int a, int b) {
	int res = a + b;
	if (res >= MOD) res -= MOD;
	return res;
}

int binPow(int a, int n) {
	if (n == 0) return 1;
	if (n & 1) return mul(a, binPow(a, n - 1));
	int res = binPow(a, n >> 1);
	return mul(res, res);
}

int f[N];

inline int C(int n, int k) {
	if (k > n) return 0;
	if (k == 0 || k == n) return 1;
	int num = f[n];
	int denom = mul(f[k], f[n - k]);
	return mul(num, binPow(denom, MOD - 2));
}

inline void add(int& a, int b) {
	a = sum(a, b);
}

int c[N][N];
int dp[N][N];

inline void solve() {
	f[0] = 1;
	for (int i = 1; i < N; i++) f[i] = mul(f[i - 1], i);
	forn(i, N) forn(j, N) c[i][j] = C(i, j);
	dp[1][1] = 1;
	bool sorted = true;
	for (int i = 2; i <= n; i++) {
		if (a[i] < a[i - 1]) sorted = false;
		if (sorted) dp[i][i] = 1;
	}

	set<int> s;
	forn1(i, n) s.insert(a[i]);
	assert(sz(s) == n);

	for (int i = 1; i < n; i++) for (int j = 1; j <= i; j++) {
		int cur = dp[i][j];
		if (cur == 0) continue;
		//cerr << "i j cur == " << i << ' ' << j << ' ' << cur << endl;
		bool sorted = true;
		int bound = min(n, i + j);
		for (int ni = i + 1; ni <= bound; ni++) {
			int nj = ni - (i + 1) + 1;
			assert(nj <= j);
			if (ni > i + 1 && a[ni] < a[ni - 1]) sorted = false;
			if (!sorted) break;
			//cerr << "ni == " << ni << endl;
			//cerr << "C == " << c[j][nj] << endl;
			//cerr << "toAdd == " << mul(cur, c[j][nj]) << endl;
			add(dp[ni][nj], mul(cur, mul(c[j][nj], f[nj])));
		}
	}

	int ans = 0;
	forn1(i, n) add(ans, dp[n][i]);
	cout << ans << endl;
	return;
}

int main() {
#ifdef _DEBUG
	assert(freopen("input.txt", "rt", stdin));
	assert(freopen("output.txt", "wt", stdout));
#endif

	cout << setprecision(10) << fixed;
	cerr << setprecision(10) << fixed;

	srand(int(time(NULL)));

	int T = 1;
	//#define MULTITEST
#ifdef MULTITEST
	assert(scanf("%d", &T) == 1);
#endif

	forn(i, T) {
#ifdef _DEBUG
		cerr << "TEST == " << i << endl;
#endif
		assert(read());
		//cout << "Case #" << i + 1 << ": ";
		solve();
		//cerr << "curTime == " << clock() << " ms" << endl;
	}

#ifdef _DEBUG
	cerr << "TIME == " << clock() << " ms" << endl;
#endif
	return 0;
}