#include <bits/stdc++.h>

#define F first
#define S second
#define llong long long
#define ullong unsigned long long
#define mp make_pair
#define pb push_back
#define pii pair <int, int>
#define sz(v) (int)v.size()
#define pt pair <double, double>
#define x first
#define y second
#define matrix vector <vector <int> >

using namespace std;

const int MXN = (int)3e6 + 10;
const int INF = (int)1e9 + 7;
const llong LINF = (llong)1e18 + 10;
const double EPS = (double)1e-6;
const double PI = (double)acos(-1.0);

int a[MXN];
int n;
int pref[MXN];
int f[MXN];
int dp[1222][1222];
int inv[MXN], inv_f[MXN];

inline int binpow(int x, int y){
  int ret = 1;
  while(y){
    if(y & 1)
      ret = (ret * 1LL * x) % INF;
    x = (x * 1LL * x) % INF;
    y >>= 1;
  }
  return ret;
}

inline bool check(int x, int y){
  return pref[y] - pref[x] == (y - x);
}

inline int A(int n, int k){
  return (f[n] * 1LL * binpow(f[n - k], INF - 2)) % INF;
}

inline int C(int n, int k){
	return (f[n] * 1LL * binpow((f[n - k] * 1LL * f[k]) % INF, INF - 2)) % INF;
}

int main(){
  #ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
  #endif
  f[0] = 1;
  for(int i = 1; i < MXN; ++i){
    f[i] = (f[i - 1] * 1LL * i) % INF;
  }           
  for (int i = 0; i < MXN; ++i){
  	inv_f[i] = binpow(f[i], INF - 2);
  }
  scanf("%d", &n);
  for(int i = 1; i <= n; ++i){
    scanf("%d", &a[i]);
    pref[i] = pref[i - 1] + (a[i] > a[i - 1]);
  }
  for(int i = 1; i <= n; ++i){
    if(check(1, i)){
      dp[i][i] = 1;
    }
  }
  for(int i = 1; i <= n; ++i){
    for(int j = 1; j + j <= i; ++j){
      for(int k = j; k + j <= i; ++k){
        if(!dp[i - j][k] || !check(i - j + 1, i)){
          continue;
        }
        //dp[i][j] += (((C(k, j) * 1LL * dp[i - j][k]) % INF) * 1LL * binpow(f[k - j], INF - 2)) % INF;
        //dp[i][j] += ((C(k, j) * 1LL * dp[i - j][k]) % INF);
        //dp[i][j] += (((dp[i - j][k] * 1LL * f[j]) % INF) * 1LL * binpow(f[k - j], INF - 2)) % INF;
      	dp[i][j] += (((dp[i - j][k] * 1LL * f[k]) % INF) * 1LL * inv_f[k - j]) % INF;
      	if(dp[i][j] >= INF)
          dp[i][j] -= INF;
      	
      }
    }
  }
  /*for(int i = 1; i <= n; ++i){
  	for(int j = 1; j <= n; ++j){
  		cout << dp[i][j] << " "; 
  	}
  	cout << "\n";
  }*/
  int ans = 0;
  for(int i = 1; i <= n; ++i){
    //ans += (dp[n][i] * 1LL * f[i]) % INF;
    //ans += (dp[n][i] * 1LL * binpow(f[i], INF - 2)) % INF;
   	//if(check(1, i))
    ans += (dp[n][i]);
    if(ans >= INF)
      ans -= INF;
  }
  /*if(check(1, n)){
  	ans -= f[n];
  	ans++;
  	ans %= INF;
  	if(ans < 0)
  		ans += INF;
  }*/
  printf("%d", ans);
  return 0;
}