#include <iostream>

using namespace std;
#define mod 1000000007
#define ll long long

ll permu[1300][1300]={{0}};

ll dp[1300][1300];
ll cum_sum[1300][1300];

void precompute()
{
	ll i,j;
	for(i=1;i<=1205;i++)
		permu[i][0] = 1;
	for(i=1;i<=1205;i++)
	{
		for(j=1;j<=i;j++)
		{
			permu[i][j] = (permu[i][j-1]*(i-j+1))%mod;
		}
	}
}

ll _sorted(ll arr[],ll st,ll end,ll n)
{
	ll val = arr[st];
	ll i = st+1;
	ll max_len = 1;
	while(i<=end&&i<=n)
	{
		if(arr[i]>val)
		{
            val = arr[i];
			i++;
			max_len++;
		}
        else
            break;
	}
	return max_len;
}

int main()
{
	ll n,i,ans,v,curr_v,len,val,j,k,arr[1300];
	precompute();
	cin >> n;
	for(i=1;i<=n;i++)
		cin >> arr[i];
				// for sizeof(V) = 1;

	/*for(v=2;v<=n;v++)
	{
		curr_v = v;
		i = 1;			//index in array
		if(_sorted(arr,i,i+v-1)==v)				//from (1,v)
		{
			i = i+curr_v;
			while(curr_v>1&&i<=n)
			{
				val = 1;					//sizeof(V) = v;
				len = _sorted(arr,i,i+curr_v-1);			//curr_v = len , will be updated later
				val = (val*permu[curr_v][len]);
				curr_v = len;
				i = i+curr_v;
			}
			ans = (ans+val)%mod;
		}
		else							//if no sorted length of size v, no length of size > v
			break;
	}*/
	for(j=0;j<=n;j++)
		dp[n+1][j] = 1;
    for(i=1;i<=n;i++)
        dp[i][1] = 1;
    //cout << n << endl;
	for(i=n-1;i>0;i--)
	{
        //cout << i << "- " <<endl;
		for(j=2;i+j-1<=n;j++)
		{
            //cout << j << " ";
			if(_sorted(arr,i,i+j-1,n)==j)
			{	
                if(i+j>n)
                    dp[i][j] = (dp[i][j]+1)%mod;
                else
                {  
                    for(k=1;k<=j;k++)
                    {
                      
                        dp[i][j] = (dp[i][j]+permu[j][k]*dp[i+j][k])%mod;
                        //cout << i <<" " << j << " " << k << endl;
                    }
                }
                //cout << dp[i][j] << ";";
			}
			else
				break;
		}	
        //cout << endl;
	}
	ans = 0;
	for(i=1;i<=n;i++)
		ans = (ans+dp[1][i])%mod;
	cout << ans << endl;
}