#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <cassert>
#include <iomanip>
#include <iostream>
#include <algorithm>
#include <unordered_set>
#include <unordered_map>

using namespace std;

#define f first
#define s second
#define pb push_back
#define pp pop_back
#define mp make_pair
#define ll long long
#define ld double
#define ull unsigned long long
#define PI pair < int, int > 

const int N = 1234;
const int M = 123;
const ld Pi = acos(-1);
const ll Inf = 1e18;
const int inf = 1e9;
const int mod = 1e9 + 7;

void add(int &a, int b) {
  a += b;
  if (a >= mod) a -= mod;
}
int mult(int a, int b) {
  return 1ll * a * b % mod;
}
int sum(int a, int b) {
  add(a, b);
  return a;
}

int n, a[N], dp[N][N], cnk[N][N], f[N];

int main() {
  #ifdef wws
    freopen("in", "r", stdin);
   // freopen("out", "w", stdout);
  #endif 
  ios_base::sync_with_stdio(0);
  cin >> n;
  for (int i = 0;i <= n;i++) {
    cnk[i][i] = cnk[i][0] = 1;
    if (i == 0) f[i] = 1;
    else f[i] = mult(i, f[i - 1]);
    for (int j = 1;j < i;j++) {
      cnk[i][j] = sum(cnk[i - 1][j], cnk[i - 1][j - 1]);
    }
  }
  for (int i = 1;i <= n;i++) {
    cin >> a[i];
  }
  reverse(a + 1, a + n + 1);
  dp[0][0] = 1;
  for (int i = 0;i <= n;i++) {
    for (int j = 0;j <= i;j++) {
      int lst = inf;
      for (int k = i + 1;k <= n;k++) {
        if (lst < a[k]) {
          break;
        }
        lst = a[k];
    //    cout << "k = " << k << endl;
        if (k - i >= j) {
          add(dp[k][k - i], mult(mult(cnk[k - i][j], f[j]), dp[i][j]));
        }
      }
  //    cout << i << " " << j << " dp = " << dp[i][j] << endl;
    }
  }
  int ans = 0;
  for (int i = 0;i <= n;i++) {
    add(ans, dp[n][i]);
  }
  cout << ans << endl;
  return 0;
}