#include <bits/stdc++.h>
#define PB push_back
#define MP make_pair
#define REP(i,n) for (int i=0;i<(n);i++)
#define ALL(a) (a).begin(),(a).end()
#define INF 1000000001
#define MOD 10000
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> P;
const ull B=100000007;
int main(){
      int n;
      while(cin>>n&&n){
            int lb=-1,ub=n,a[n],cnt=0,k;
            REP(i,n)cin>>a[i];
            cin>>k;
            while(ub-lb>1){
                  int mid=(lb+ub)/2;
                  cnt++;
                  if(k==a[mid])break;
                  if(a[mid]>k)ub=mid;
                  else lb=mid;
            }
            cout<<cnt<<endl;
      }
}