#include <stdio.h>

int main(void)
{
	int n;
	int x[100];
	int i;
	int max, min;
	int obj;
	int ans;
	
	while (1){
		scanf("%d", &n);
		
		if (n == 0)break;
		
		for (i = 0; i < n; i++){
			scanf("%d", &x[i]);
		}
		
		scanf("%d", &obj);
		
		max = n - 1;
		min = 0;
		ans = 0;
		while (1){
			
			i = (max + min) / 2;
			if (x[i] < obj){
				min = i + 1;
			}else if (x[i] > obj){
				max = i - 1;
			}else{
				break;
			}
			
			ans++;
			
			if (max == min){
				ans++;
				break;
			}
		}
		
		printf("%d\n", ans);
	}
	
	return (0);
}