#include<iostream>
#include<string>
#include<algorithm>
#include<map>
#include<set>
#include<utility>
#include<vector>
#include<cmath>
#include<cstdio>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define pb push_back
#define mp make_pair
#define it ::iterator
#define all(in) in.begin(),in.end()
const double PI=acos(-1);
const double ESP=1e-10;
using namespace std;
int main(){
  int n;
  while(cin>>n,n){
    vector<int>in(n);
    rep(i,n)cin>>in[i];
    int t=0,l=n-1;
    int co=0;
    int out;
    cin>>out;
    while(t<=l){
      int tmp=(t+l)/2;
      //tmp=in[tmp];
      co++;
      if(in[tmp]==out)break;
      if(in[tmp]<out)t=tmp+1;
      if(in[tmp]>out)l=tmp-1;
    }
    cout<<co<<endl;
  }

}