import java.util.*;
public class Main{
public static void main(String args[]){
Scanner sc = new Scanner(System.in);
int t = sc.nextInt();
int n = sc.nextInt();
int k = sc.nextInt();
int arr [] = new int [ k- n];
for(int i = k ; i< n ; i++){
arr[i] = sc.nextInt();
}
kthRoot( arr, n, k);
}
public static void kthRoot( int arr[] , int n, int k){
int left = k ;
int right = n ;
int ans ;
int mid ;
while (left < right){
mid = (left + right)/2 ;
int d = mid ^ left;
if( d <= n){
mid = mid + 1 ;
left = mid ;
right = n ;
ans = mid;
}
else if(d >= n){
mid = mid - 1 ;
ans = mid ;
left = k;
right = mid ;
}
else
ans = mid ;
System.out.println(ans);
}
}
}