#include <cstdio>

int main(){
  int n,key;

  while(scanf("%d" ,&n) ,n){
    int a[n];
    for(int i = 0 ; i < n ; i++){
      scanf("%d" ,a + i);
    }

    scanf("%d" ,&key);

    int lb = 0,ub = n-1,cnt = 0;
    while(ub - lb >= 0){
      int mid = (lb + ub) / 2;
      cnt++;

      if(key == a[mid]){
	break;
      }

      if(key < a[mid]){
	ub = mid - 1;
      }else{
	lb = mid + 1;
      }
    }   
    printf("%d\n" ,cnt);
  }

  return 0;
}