#include <cstdio>
#include <cstring>
#include <iostream>

using namespace std;

typedef long long int Lint;

const int MAXN = 2000;
const Lint MOD = 1e9+7;

int N;
int ar[MAXN];

Lint factorial[MAXN];
Lint dn[MAXN][MAXN];
Lint permutation[MAXN][MAXN];

Lint fast_power( Lint base , int power ){
	
	if( power == 0 )
		return 1LL;
	if( power == 1 )
		return base;
	
	Lint next = fast_power(base,power>>1);
	
	if( power&1 )
		return (next*next*base)%MOD;
	return (next*next)%MOD;
}

Lint f( int place , int last ){

	Lint &rev = dn[place][last];
	
	if( rev != -1 )
		return rev;
	
	if( place == N+1 )
		return rev=1;
	
	if( place == 1 )
		rev = f(place+1,1);
	else
		rev = (f(place+1,1)*last)%MOD;
	
	for( int i=1 ; i<last && place+i <= N; i++ )
		if( ar[place+i]<ar[place+i-1] )
			break;
		else if( place == 1 )
			rev = (rev+f(place+i+1,i+1))%MOD;
		else
			rev = (rev+((f(place+i+1,i+1)*permutation[last][i+1])%MOD))%MOD;
			//~ rev = (rev+(f(place+i+1,i+1)*((factorial[last]*((fast_power((factorial[last-i-1]*factorial[i+1])%MOD,MOD-2)*factorial[i+1])%MOD))%MOD)))%MOD;
	
	//~ cerr << place << ' ' << last << ' ' << rev << endl;
	return rev;
}

int main(){
	
	
	scanf("%d",&N);
	
	memset(dn,-1,sizeof dn);
	
	factorial[0] = 1LL;
	
	for( int i=1 ; i<=N+2 ; i++ )
		factorial[i] = ((Lint)i*factorial[i-1])%MOD;
	
	for( int i=1 ; i<=N ; i++ ){
		
		permutation[i][1] = i;
		
		for( int j=2 ; j<=i ; j++ )
			permutation[i][j] = (permutation[i][j-1]*(i-j+1))%MOD;
	}
	
	for( int i=1 ; i<=N ; i++ )
		scanf("%d",ar+i);
	
	printf("%lld\n",f(1,N));
	
	return 0;
}