#include<stdio.h>
typedef struct Node{
    int data;
}node;
int main(){
    int n,l;
    scanf("%d",&n);
    scanf("%d",&l);
    int arr[n];
    for(int i=0;i<n;i++){
        scanf("%d",&arr[i]);
    }
    int count=0;
    int level=0;
    int node=1;
    int sum=0;
    for(int i=0;i<n;i++){
        if(level==l){
            sum=arr[i].data;
        }
        count++;
        if(count==node){
            level++;
            node*=2;
            count=0;
        }
    }
    printf("%d",sum);
}