import java.util.Scanner;

public class No1020 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int k = sc.nextInt();
        String str = sc.next();
        char[] c = str.toCharArray();
        for(int i=0;i<n;i++) {
            if(i<(n-k+1)) {
                System.out.print(c[i+k-1]);
            }else{
                if((n-k)%2==1){
                    System.out.print(c[i-(n-k+1)]);
                }else{
                    System.out.print(c[n-i-1]);
                }
            }
        }
        System.out.println("");
    }
}