#include<bits/stdc++.h>

using namespace std;

const int MOD = 1e9+7;
int n, arr[1200];
long long cache[1200][1201];
long long comb[1201][1201];
long long fac[1201];

long long val(int a, int b)
{
	return (comb[a][b] * fac[b]) % MOD;
}

long long f(int idx, int sz)
{
	if(idx == n)	return 1;

	long long& result = cache[idx][sz];
	if(result != -1)	return result;

	int pre = 0;
	result = 0;
	for(int i = idx; i < n; i++)
	{
		if((pre > arr[i]) || (i-idx+1 > sz))	break;
		result = (result + f(i+1, i-idx+1) * ((idx==0)?1:val(sz, i-idx+1))) % MOD;
		pre = arr[i];
	}
	return result;
}

int main(void)
{
	comb[0][0] = 1;
	fac[0] = 1;

	for(int i = 1; i <= 1200; i++)
	{
		comb[i][0] = comb[i][i] = 1;
		for(int j = 1; j < i; j++)
			comb[i][j] = (comb[i-1][j-1] + comb[i-1][j]) % MOD;
		fac[i] = (fac[i-1] * i) % MOD;
	}

	scanf("%d", &n);
	for(int i = 0; i < n; i++)
		scanf("%d", arr+i);

	memset(cache, -1, sizeof(cache));
	printf("%lld\n", f(0, n));
	return 0;
}