#include<bits/stdc++.h>
#define x first
#define pb push_back
#define mp make_pair
#define y second
#define all(a) a.begin(), a.end()
#define l(x) (x<<1)
#define r(x) ((x<<1) | 1)
#define f(x) x>>1
#define lsb(x) (x&(-x))
using namespace std;
typedef long long LL;
typedef long double LD;
typedef vector<LL> VLL;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<int> VI;
typedef VI::iterator vit;
typedef tuple<int,int,int> PIII;
const LL INF=1e6;
const int NMAX=2255;
const int LOGMAX=18;
const int MOD=1000000007;
const LD pi=acos(-1.0);

LL n, A[NMAX], dp[NMAX][NMAX], m[NMAX], fact[NMAX], bin[NMAX][NMAX];

void solve(){
  cin>>n;
  for(int i=1; i<=n; ++i)
    cin>>A[i];
  fact[0]=1;
  for(int i=1; i<=n; ++i){
    fact[i]=(1LL*i*fact[i-1])%MOD; 
  }

  for(int i=0; i<=n; ++i)
    bin[i][0]=1;

  for(int i=1; i<=n; ++i){
    for(int j=1; j<=n; ++j)
    {
      bin[i][j]=(bin[i-1][j] + bin[i-1][j-1])%MOD;
    }
  }

  A[0]=1000000;
  for(int i=1; i<=n; ++i)
  {
    if(A[i] < A[i-1])
      m[i]=1; 
    m[i]+=m[i-1];
  }



  dp[0][0]=1;

  for(int j=1; j<=n; ++j)
  {
    for(int i=1; i<=j; ++i)
    {
      if(m[n-j+i] - m[n-j] == 0 || ((m[n-j+i] - m[n-j] == 1) && (m[n-j+1]-m[n-j])==1)){
        for(int k=0; k<=i; ++k)
          dp[i][j]=(dp[i][j] + (1LL* ((1LL * bin[i][k] * fact[k])%MOD) * dp[k][j-i])%MOD)%MOD;
      }
      //cout<<dp[i][j]<<" ";
    }
    //cout<<"\n";
  }
  int rs=0;
  for(int i=1; i<=n; ++i){
    rs=(rs+dp[i][n])%MOD; 
  }
  cout<<rs<<"\n";


}

int main()
{
    cout<<setprecision(6)<<fixed;
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    solve();
    
    return 0;
}