#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <functional>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <utility>
#include <sstream>
#include <complex>

using namespace std;

#define FOR(i,a,b) for(long long i=(a);i<(b);i++)
#define REP(i,N) for(long long i=0;i<(N);i++)
#define ALL(s) (s).begin(),(s).end()
#define fi first
#define se second

#define PI acos(-1.0)
#define INF 1000000007
#define EPS 1e-10

typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<double, double> PD;
typedef pair<string, ll> PS;
typedef vector<ll> V;
typedef pair<P, char> PC;

int n, ans, a[1000], res;

int main(){
	while (cin >> n&&n){
		res = 0;
		fill(a, a + 1000, 0);
		REP(i, n)cin >> a[i];
		cin >> ans;
		int lb = -1, ub = n;
		while (ub - lb > 1){
			/*cout << ub << " " << lb << endl;*/
			int mid = (ub + lb) / 2;
			if (a[mid] < ans){
				lb = mid;
				res++;
			}
			else if (a[mid] > ans){
				ub = mid;
				res++;
			}
			else{
				res++;
				break;
			}
		}
		cout << res << endl;
	}
}