#include<bits/stdc++.h>
using namespace std;
int a[10000000],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(){
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>a[i];
	} 
	cin>>x;
	f(0,n-1);
	cout<<o+1;
	return 0;
}

/**************************************************************
	Problem: 1236
	User: houshanglin
	Language: C++
	Result: Time Limit Exceed
****************************************************************/