import java.io.IOException;
import java.io.InputStream;
import java.util.NoSuchElementException;

class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte(){
        if(ptr < buflen){
            return true;
        }else{
            ptr = 0;
            try{
                buflen = in.read(buffer);
            }catch(IOException e){
                e.printStackTrace();
            }
            if(buflen <=0){
                return false;
            }
        }
        return true;
    }

    private int readByte(){
        if(hasNextByte())return buffer[ptr++];
        else return -1;
    }

    private static boolean isPrintableChar(int c){
        return 33<=c && c<=126;
    }
    public boolean hasNext(){
        while(hasNextByte() && !isPrintableChar(buffer[ptr]))ptr++;
        return hasNextByte();
    }

    public String next(){
        if(!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)){
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    public long nextLong(){
        if(!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if(b == '-'){
            minus = true;
            b = readByte();
        }
        if(b < '0' || '9' < b){
            throw new NumberFormatException();
        }
        while(true){
            if('0' <= b && b<='9'){
                n*=10;
                n+=b-'0';
            }else if(b==-1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt(){
        long nl = nextLong();
        if(nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)throw new NumberFormatException();
        return (int) nl;
    }
    public double nextDoutble(){return Double.parseDouble(next());}
}
public class Main {
    public static void main(String[] args) {
        FastScanner fs = new FastScanner();
        int n = fs.nextInt();
        long k = fs.nextLong();
        long[] a = new long[n];
        for(int i=0;i<n;i++){
            a[i] = fs.nextLong();
        }
        int maxDigit = 60;
        //上からi+1ビット目の立っているビット数
        int[] nums = new int[maxDigit];
        for(int i=0;i<maxDigit;i++){
            long mask = 1L<<(maxDigit-i-1);
            for(int j=0;j<n;j++){
                if((mask & a[j])>0){
                    nums[i]++;
                }
            }
        }

        //
        long[][] dp = new long[maxDigit+1][2];
        for(int i=0;i<=maxDigit;i++)for(int j=0;j<2;j++)dp[i][j] = -1;
        dp[0][0] = 0;
        for(int i=0;i<maxDigit;i++){
            long mask = 1L<<(maxDigit-i-1);
            long cost0 = mask*(nums[i]);
            long cost1 = mask*(n-nums[i]);
            if(dp[i][1]!=-1){
                dp[i+1][1] = Math.max(dp[i+1][1],dp[i][1]+Math.max(cost0,cost1));
            }

            if(dp[i][0]!=-1){
                if((k & mask)>0){
                    dp[i+1][1] = Math.max(dp[i+1][1],dp[i][0]+cost0);
                }
            }

            if(dp[i][0]!=-1){
                if((k & mask)>0){
                    dp[i+1][0] = Math.max(dp[i+1][0],dp[i][0]+cost1);
                }else{
                    dp[i+1][0] = Math.max(dp[i+1][0],dp[i][0]+cost0);
                }
            }

        }

        System.out.println(Math.max(dp[maxDigit][0],dp[maxDigit][1]));
        

    }
}

Measured memory_bytes: 23240