Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int[] arr = new int[n];
for(int i =0; i <n;i++) {
arr[i] = sc.nextInt();
}
int num = sc.nextInt();
//Binary Search
int low= 0;
int high=n-1;
int mid = (low+high)/2;
if(arr[mid]<num) {
low=mid+1;
}
else if(arr[mid]>num) {
high= mid-1;
}else if(arr[mid]==num) {
System.out.println(mid);
}else {
System.out.println("Not Found");
}