#include <stdio.h>  

int v[100], n, x;  

int binar (int ls, int ld)  
{  
    if (ls==ld)  
        if (v[ls]==x)  
            return ls;  
    if (x<v[(ls+ld)/2])  
        return binar (ls, (ls+ld)/2);  
    else  
        return binar ((ls+ld)/2+1, ld);  
}  

int main ()  
{
	freopen ("cautbin.in", "r", stdin);  
    freopen ("cautbin.out", "w", stdout);  
      
    scanf ("%d", n);  
    for (int i=1; i<n; i++)  
        scanf ("%d", v[i]);  
    scanf ("%d", x);  
   printf ("%d", binar (1, n));  
}