#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define fbo find_by_order
#define ook order_of_key
 
typedef long long ll;
typedef pair<ll,ll> ii;
typedef vector<int> vi;
typedef long double ld; 
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> pbds;
typedef set<int>::iterator sit;
typedef map<int,int>::iterator mit;
typedef vector<int>::iterator vit;

int a[1201];
const int MOD = 1e9 + 7;
ll dp[1201][1201];
ll nxt[1201];
ll ifact[1201];
ll fact[1201];

ll modpow(ll x,ll b)
{
	ll r=1;
	while(b)
	{
		if(b&1) r=(r*x)%MOD;
		x=(x*x)%MOD;
		b>>=1;
	}
	return r;
}

ll inv(ll x) 
{
	return modpow(x,MOD-2);
}

ll d[1201][1201];
ll c(ll n, ll r)
{
	if(r==0) return 1;
	if(n<r) return 0;
	if(n==r) return 1;
	if(d[n][r]!=-1) return d[n][r];
	return (d[n][r]=(c(n-1,r-1)+c(n-1,r))%MOD);
}

int main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	int n; cin>>n;
	memset(d,-1,sizeof(d));
	for(int i = 0; i < n; i++)
	{
		cin>>a[i];a[i]--;
	}
	fact[0]=1;
	for(int i=1;i<=1200;i++) fact[i]=(fact[i-1]*i)%MOD;
	ifact[0]=1;
	for(int i=1;i<=1200;i++) ifact[i]=inv(fact[i]);
	nxt[n-1]=n-1;
	for(int i = n - 2; i >= 0; i--)
	{
		if(a[i]<a[i+1]) nxt[i]=nxt[i+1];
		else nxt[i]=i;
	}
	/*
	for(int i = 1; i <= n; i++)
	{
		dp[n-1][i] = 1;
		dp[n][i] = 1;
	}
	*/
	dp[n][0]=1;
	dp[n-1][1]=1;
	for(int i = n - 2; i >= 0; i--)
	{
		for(int j = 1; j <= n; j++)
		{
			if(j<=nxt[i]-i+1)
			{
				for(int k = 0; k <= j; k++)
				{
					dp[i][j] = (dp[i][j] + ((dp[i+j][k]*fact[j])%MOD*c(j,k))%MOD)%MOD;
				}
			}
			//cerr<<i<<' '<<j<<' '<<dp[i][j]<<'\n';
			//if(i>0) dp[i][j] = (dp[i][j]+dp[i][j-1])%MOD;
		}
	}
	ll ans = 0;
	for(int i = 1; i <= n; i++)
	{
		ans=(ans+(dp[0][i]*ifact[i])%MOD)%MOD;
	}
	cout<<ans;
}