#include <iostream>
#include <math.h>
using namespace std;
int main(){
    int a, b, i1, times, max, min, tyuusinn;
    while(1){
        cin >> a;
        if(a==0){break;}
        i1=0;
        int w[a];
        while(1){
                cin >> b;
                w[i1]=b;
                i1++;
                if(i1==a){break;}
        }
        max=a-1;
        min=0;
        times=0;
        cin >> b;
        while(1){
            times++;
            tyuusinn=(max+min)/2;
            if(max<=min){break;}
            if(w[tyuusinn]==b){break;}
            else if(w[tyuusinn]<b){
                min=tyuusinn+1;
            }
            else{
                max=tyuusinn-1;
            }
        }
        cout << times << endl;
    }
    return 0;
}