#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <vector>
#include <map>
#include <cstdlib>
#include <set>
#include <stack>
#include <queue>
using namespace std;

#define X first
#define Y second
#define N 1210
typedef long long ll;
typedef pair<int,int> pii;

const int INF=1<<30;
const int Mod=1000000000+7;
int n;
int a[N],dp[N][N],c[N][N],A[N][N],fac[N];

int Solve(int p,int k)
{
	if (p>n) return 1;
	if (dp[p][k]!=-1) return dp[p][k];
	
	int &res=dp[p][k]=0;
	
	for (int i=p;i<=n && i-p+1<=k;i++)
	{
		if (i!=p && a[i]<a[i-1]) break;
		res+=1ll*Solve(i+1,i-p+1)*A[k][i-p+1]%Mod;
		if (res>=Mod) res-=Mod;
	}
	return res;
}

int main()
{
	//freopen("in.in","r",stdin);
	//freopen("out.out","w",stdout);
		
	fac[0]=1;
	for (int i=1;i<N;i++) fac[i]=1ll*fac[i-1]*i%Mod;
	c[0][0]=1;
	for (int i=1;i<N;i++)
	{
		c[i][0]=A[i][0]=1; 
		for (int j=1;j<=i;j++) c[i][j]=(c[i-1][j-1]+c[i-1][j])%Mod,A[i][j]=1ll*c[i][j]*fac[j]%Mod;
	}	
	
	memset(dp,-1,sizeof(dp));
	scanf("%d",&n);
	for (int i=1;i<=n;i++) scanf("%d",&a[i]);
	
	int res=0;
	for (int i=1;i<=n;i++)
	{
		if (i!=1 && a[i]<a[i-1]) break;
		res+=Solve(i+1,i);
		if (res>=Mod) res-=Mod;
	}
	printf("%d\n",res);
	return 0;
}