#include<iostream>
#include<fstream>
#include<string>
#include<algorithm>
#include<queue>
#include<cctype>
#include<numeric>
#include<iterator>
#include<set>
#include<map>
#include<vector>
#include<sstream>
#define myforeach(c,it,type) for(type::iterator it = c.begin(); it != c.end(); it++)

using namespace std;
int main(void)
{
    int n;
    ifstream is("permutation.txt");

    while(is >> n && n){
        vector<bool> isPlus;
        {
            int before;
            int m = n;
            is >> before;
            int curr;
            --m;
            while(m--){
                is >> curr;
                if(before < curr){
                    isPlus.push_back(true);
                }else{
                    isPlus.push_back(false);
                }
                before = curr;
            }
        }
        if ( n<=2 ) {
            cout<<1<<endl;
            continue;
        }
        vector<unsigned> tab1(2,0);//, tab2(n,0);
        tab1.reserve(n);
        if ( isPlus[0] ) {
            tab1[0]=0;
            tab1[1]=1;
        }
        else{
            tab1[0]=1;
            tab1[1]=0;
        }
        
        for ( int cur=3 ; cur<=n ; cur++ ) {
            if ( isPlus[cur-2] ) {
                tab1.insert(tab1.begin(),0);
                for ( int i=1 ; i<cur ; i++ ) {
                    tab1[i]=tab1[i-1]+tab1[i];
                }
            }
            else {
                tab1.resize(cur);
                tab1[cur-1]=0;
                for ( int i=cur-2 ; 0<=i ; i-- ) {
                    tab1[i] = tab1[i+1]+tab1[i];
                }
            }
            /*cout<<"test ";
            copy(isPlus.begin(), isPlus.begin()+(cur-1),
                 ostream_iterator<bool>(cout,""));
            cout<<" is ";
            copy(tab1.begin(), tab1.begin()+cur,
                 ostream_iterator<unsigned>(cout," "));
            cout<<endl;*/
        }
        unsigned sum=accumulate(tab1.begin(), tab1.begin()+n, (unsigned)0);
        cout<<sum<<endl;
    }
}