#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#define FF 1000000007
using namespace std;

int main() {
    long long n;
    cin>>n;
    vector<long long> vin(n);
    vector<bool> isbreak(n, false);
    for (long long i=0; i<n; i++){
        cin>>vin[i];
    }
    for (long long i=1; i<n; i++){
        if (vin[i]<vin[i-1]){
            isbreak[i]=true;
        }
    }
    vector<vector<long long> > D(n+1, vector<long long> (n+1,1));
    for (long long row=2; row<=n; row++){
        for (long long col=n-1; col>=0; col--){
            if (col==0 || col-row>=0){
                long long s=0;
                long long link=1;
                long long accCol=col+link;
                long long accRow=1;
                long long fac=row;
                long long mult=fac;
                while (accCol<=n && link<=row){
                    if (col>0){
                       s=(s+(mult*D[accRow][accCol])%FF)%FF; 
                    }
                    else if (col==0 && accRow==row){
                        s=D[accRow][accCol];
                    }
                    if (isbreak[accCol]){
                        break;
                    }
                    accRow++;
                    accCol++;
                    link++;
                    fac--;
                    mult=(mult*fac)%FF;
                }
                D[row][col]=s;
            }
        }
    }
    long long result=0;
    for (long long row=1; row<=n; row++){
        /*for (long long col=0; col<n; col++){
            cout<<D[row][col]<<" ";
        }
        cout<<endl;*/
        result=(result+D[row][0])%FF;
    }
    cout<<result;
    return 0;
}