#include<bits/stdc++.h>
using namespace std;
int a[1000000],n,x,o=-1;
void f(int l,int r){
	int m=(l+r)/2;
	if(a[m]==x){
		o=m;
	}
	else if(a[m]>x) f(l,m-1);
	else f(m+1,r);
}
int main(){
	scanf("%d",&n); 
	for(int i=0;i<n;i++){
		scanf("%d",&a[i]); 
	} 
	scanf("%d",&x); 
	f(0,n-1);
	printf("%d",o+1);
	return 0;
}
/**************************************************************
	Problem: 1236
	User: houshanglin
	Language: C++
	Result: Time Limit Exceed
****************************************************************/