#include <bits/stdc++.h>
using namespace std;
//debug
#ifdef grief
#define debug(...) do{\
	fprintf(stderr , "%s - %d : (%s) = " , __PRETTY_FUNCTION__ , __LINE__ , #__VA_ARGS__ );\
	_DO(__VA_ARGS__);\
}while(0)
template<typename I> void _DO(I&&x){
	cerr<<x<<endl;
}
template<typename I,typename...T> void _DO(I&&x,T&&...tail){
	cerr<<x<<" , ";
	_DO(tail...);
}
#else
#define debug(...)
#endif
//type
typedef long long ll;
typedef pair<int,int> pii;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef priority_queue<pll,vector<pll>,greater<pll> > heap;
//macro
#define SZ(x) ((ll)(x).size())
#define ALL(x) (x).begin(),(x).end()
#define F first
#define S second
#define REP(i,n) for(ll i=0;i<(n);i++)
#define REP1(i,a,b) for(ll i=(a);i<=(b);i++)
#define mkp make_pair
#define pb push_back
const ll INF=1e18;
const ll MA=1210;
const ll MOD=1e9+7;
//}}}
ll ran[MA];
ll rev[MA];
void llgcd(ll a,ll b,ll &x,ll &y){
	if(a==0){
		x=0; y=1;
		return;
	}
	llgcd(b%a,a,y,x);
	x-=b/a*y;
}
void build(){
	ran[0]=ran[1]=1;
	for(int i=2;i<MA;i++){
		ran[i]=ran[i-1]*i;
		ran[i]%=MOD;
	}
	rev[0]=rev[1]=1;
	ll x,y;
	for(int i=2;i<MA;i++){
		llgcd(ran[i],MOD,x,y);
		rev[i]=x;
		if(rev[i]<0)	rev[i]+=MOD;
		assert(rev[i]*ran[i]%MOD==1);
	}
}
ll n;
ll dp[MA][MA];
int arr[MA];
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	build();
	cin>>n;
//	assert(n<100);
	for(int i=1;i<=n;i++)	cin>>arr[i];
	int de=0;
	for(int i=1;i<n;i++){
		if(arr[i]<arr[i-1])	break;
		dp[i][i]=ran[i];
	}
	
	
	for(int i=1;i<=n;i++){
		
		if(arr[i]<arr[i-1])	de=i-1;
		
		for(int j=1;j<i;j++){
			int ij=i-j;
			if(ij<de)	break;
			for(int k=j;k<=ij;k++){
				dp[i][j]+=dp[ij][k]*rev[k-j];
				dp[i][j]%=MOD;
			}
//			cout<<dp[i][j]<< ' ';
			if(i<n){
				dp[i][j]*=ran[j];
				dp[i][j]%=MOD;
			}
		}
//		cout<< '\n';
	}
	
	ll ans=(de==0);
	for(int i=1;i<n;i++){
		ans+=dp[n][i];
		
		ans%=MOD;
	}
	cout<<ans<< '\n';
	
	return 0;
}