#include <iostream>
#include <algorithm>
using namespace std;

int T[100010];
int find(int m,int x){
	int r=0,l=m,ans=0;
	while(1){
		ans++;
		if(T[(r+l)/2]==x)return ans;
		else if(r>=l)break;
		if(T[(r+l)/2]>x)l=(r+l)/2-1;
		else if(T[(r+l)/2]<x)r=(r+l)/2+1;
	}
	return ans;
}
int main(){
	int n,k,num,ans;
	while(1){
		cin>>n;
		if(n==0)break;
		for(int i=0;i<n;i++){
			cin>>T[i];
		}
		cin>>k;
		ans=find(n,k);
		cout<<ans<<endl;
	}
	return 0;
}