#include <stdio.h>
#include <cctype>
#include <limits.h>
#include <math.h>
#include <complex>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <cstring>
#include <string>
#include <sstream>
#include <algorithm>
#include <iomanip>
#include <iostream>

#define VARIABLE(x) cerr << #x << "=" << x << endl
#define BINARY(x) static_cast<bitset<16> >(x);
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define REP(i,m,n) for (int i=m;i<(int)(n);i++)
#define if_range(x, y, w, h) if (0<=(int)(x) && (int)(x)<(int)(w) && 0<=(int)(y) && (int)(y)<(int)(h))

const int INF = 1000000000;
const double EPS = 1e-8;
const double PI = 3.14159;
int dx[4]={-1, 0, 1, 0}, dy[4]={0, -1, 0, 1};
using namespace std;
typedef pair<int, int> P;

/** Problem0188 : Search **/
int main()
{
	int N;
	while (cin>>N, N) {
		vector<int> a(N);
		rep(i, N) cin>>a[i];
		int t; cin>>t;
		int ans=0;
		
		int l=0, r=N-1;
		while (l<=r) {
			ans++;
			int m=(l+r)/2;
			if (a[m] == t) {
				break;
			} else if (a[m]> t) {
				r = m-1;
			} else {
				l = m+1;
			}
		}
		cout << ans << endl;
	}
}