#include <iostream>

using namespace std;

const int MAX = 1000000007;

long long factorial(int a){
    long long total=1;
    for(int i=2; i < a; i++){
        total*=i;
        total %= MAX;
    }
    return total;
}
long long poss(long long arr[], int length, int prevLength){
    if(length == 0 || prevLength == 1){
        return 1;
    }
    int sortedLength=1;
    for(int i = 0; i < min(length - 1, prevLength - 1); i++){
        if(arr[i+1] >= arr[i]){
            sortedLength++;
        }else{
            break;
        }
    }
    long long total=0;
    for(int i=1; i <= sortedLength; i++){
        total+=factorial(i)*poss(arr+i, length - i, i);
        total%=MAX;
    }
    return total%=MAX;
}

int main()
{
    int N;
    cin>>N;

    long long arr[N];
    for(int i = 0; i < N; i++){
        cin>>arr[i];
    }
    cout<<poss(arr, N, N);
}