#include <bits/stdc++.h>
#define rep(i,a,n) for(int i=a;i<n;i++)
#define repb(i,a,b) for(int i=a;i>=b;i--)
#define all(a) a.begin(),a.end()
#define o(a) cout<<a<<endl
#define int long long
#define fi first
#define se second
using namespace std;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pii;

signed main() {
	int n, x;
	while (1) {
		cin >> n;
		if (n == 0) break;
		vi d(n);
		rep(i, 0, n) {
			cin >> d[i];
		}
		cin >> x;
		int cnt = 0, l = 0, r = n - 1;
		while (l<=r) {
			cnt++;
			int mid = (l + r) / 2;
			if (d[mid] > x) {
				r = mid - 1;
			}
			else if (d[mid] < x) {
				l = mid + 1;
			}
			else if(d[mid]==x){
				break;
			}
		}
		cout << cnt << endl;
	}
}