#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <unordered_map>
#include <cstring>
#include <ctime>
#include <queue>
#include <map>
using namespace std;
typedef long long ll;
const int maxn = 1205;
const int mod = 1000000007;

void gcd(ll a,ll b, ll& d,ll& x,ll& y) {
  if(!b) {
    d=a;
    x=1;
    y=0;
  } else   {
    gcd(b,a%b,d,y,x);
    y-=a/b*x;
  }
}
ll inv(ll a,ll n)  {
  ll d,x,y;
  gcd(a,n,d,x,y);
  return d==1?(x%n+n)%(n/d):-1;
}

int n,a[maxn],b[maxn];
ll f[maxn][maxn],p[maxn][maxn],ni[maxn];

void init() {
  cin>>n;
  for(int i=1; i<=n; i++)cin>>a[i];
  b[n] = n;
  for(int i = n-1; i>=1; i--) b[i] = (a[i] < a[i+1]?b[i+1]:i);
  for(int i=1;i<maxn;i++){
    p[i][i]=1;
    for(int j=i+1;j<maxn;j++)
    p[i][j]=p[i][j-1]*j%mod;
  }
  for(int i=1;i<maxn;i++)ni[i]=inv(i,mod);
}

int main() {
 // freopen("in.cpp","r",stdin);
  init();
  for(int j=1;j<=n;j++)
  for(int i=n+1-j;i>=1;i--){
    if(b[i]<i+j-1)continue;
    if(i+j-1==n)f[i][j]=1;
    ll tmp = p[1][j];
    for(int k=j;k<i;k++){
      int r=i-k;
      if(b[r]<r+k-1)break;
      //if(i==3&&j==1)cout<<r<<","<<k<<endl;
      f[r][k]=(f[r][k]+f[i][j]*tmp%mod)%mod;
      tmp=tmp*(k+1)%mod*ni[k-j+1]%mod;
    }
  }
  int ret=0;
  //cout<<"debug:"<<f[3][1]<<endl;
  for(int i=1;i<=n;i++)ret=(ret+f[1][i])%mod;
  cout<<ret<<endl;
  return 0;
}