Being a nonconformist, Volodya is displeased with the current state of things, particularly with the order of natural numbers (natural number is positive integer number). He is determined to rearrange them. But there are too many natural numbers, so Volodya decided to start with the first n. He writes down the following sequence of numbers: firstly all odd integers from 1 to n (in ascending order), then all even integers from 1 to n (also in ascending order). Help our hero to find out which number will stand at the position number k.

Input

The only line of input contains integers n and k (1 ≤ k ≤ n ≤ 1012).

Please, do not use the %lld specifier to read or write 64-bit integers in C++. It is preferred to use the cin, cout streams or the %I64d specifier.

Output

Print the number that will stand at the position number k after Volodya's manipulations.

Examples

Input

10 3


Output

5

Input

7 7


Output

6

Note

In the first sample Volodya's sequence will look like this: {1, 3, 5, 7, 9, 2, 4, 6, 8, 10}. The third place in the sequence is therefore occupied by the number 5.
import java.io.*;
import java.util.*;


public class A318_EvenOdds {

    static class Code {
    	
        private void solve(InputReader in, OutputWriter out) throws IOException {
            long n=in.readLong();
            long k=in.readLong();
            long ans=0;
            if(n%2==0) {
            	long m=n/2;
            	if(k<=m) {
            		ans=2*k-1;
            	}
            	else {
            		k=k-m;
            		ans=2*k;
            	}
            }
            else {
            	long m=n/2+1;
            	if(k<=m) {
            		ans=2*k-1;
            	}
            	else {
            		k=k-m;
            		ans=2*k;
            	}
            }
            
            out.printLine(ans);
            out.close();
        }
    }
    
    static class ArrayOpn{
    	private int[] aI(InputReader in, int n) {
        	int A[]= new int[n];
        	for(int i=0; i<n; i++) {
        		A[i]=in.readInt();
        	}
        	return A;
        }
    	
    	static final Random random = new Random();
        
        private void sort(int A[]) {
            int n = A.length;
            for(int i=0; i<n; i++)
            {
                int j = random.nextInt(n),temp = A[j];
                A[j] = A[i];
                A[i] = temp;
            }
            Arrays.sort(A);
//            return A;
    	}
        
        private int[][] mI(InputReader in, int n, int m){
        	int A[][]= new int[n][m];
        	for(int i=0; i<n; i++) {
        		for(int j=0; j<m; j++) {
        			A[i][j]=in.readInt();
        		}
        	}
        	return A;
        }
        
        private int minEl(int A[]) {
        	int min=Integer.MAX_VALUE;
        	for(int e: A) {
        		min=Math.min(e, min);
        	}
        	return min;
        }
        private int maxEl(int A[]) {
        	int max=Integer.MIN_VALUE;
        	for(int e: A) {
        		max=Math.max(e, max);
        	}
        	return max;
        }
        
        private int occurence(int A[], int e) {
        	int c=0;
        	for(int k: A) {
        		if(k==e) {
        			c++;
        		}
        	}
        	return c;
        }
        
        public int linears(int A[], int e) {
        	
        	for(int i=0; i<A.length; i++) {
        		if(A[i]==e) {
        			return i;
        		}
        	}
        	return -1;
        }
        
        public int binarys(int A[], int e) {
        	int low=0, high=A.length-1;
        	while(low<=high) {
        		int mid=(low+high)/2;
        		if(A[mid]==e) {
        			return mid;
        		}
        		else if(A[mid]<e) {
        			low=mid+1;
        		}
        		else {
        			high=mid-1;
        		}
        	}
        	return -1;
        }
        
        public void printAr(OutputWriter out, int A[]) {
        	for(int e: A) {
        		out.print(e+" ");
        	}
        }
    }
    
    static class Pair<F, S>{
        private final F first; //first member of pair
        private final S second; //second member of pair

        private Pair(F first, S second) {
            this.first = first;
            this.second = second;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }

            if (o == null || getClass() != o.getClass())
                return false;

            Pair<? , ?> pair = (Pair<?, ?>) o;
            if(!first.equals(pair.first))
                return false;
            return second.equals(pair.second);
        }

        @Override
        public int hashCode() {
            return 31 * first.hashCode() + second.hashCode();
        }

        @Override
        public String toString() {
            return "(" + first +", "+ second +")";
        }


        public static <F,S> Pair<F,S> of(F a, S b) {
            return new Pair<>(a,b);
        }
        public F getFirst() {
            return first;
        }

        public S getSecond() {
            return second;
        }
    }
    
    // Comparator for using in Sorting On integers
    static class PairCompare implements Comparator<Pair<Integer, Integer>> {
        @Override
        public int compare(Pair<Integer, Integer> p1, Pair<Integer, Integer> p2) {
            int diff = Integer.compare(p1.first, p2.first);
            if(diff == 0) {
                return Integer.compare(p1.second, p2.second);
            }
            else return diff;
        }
    }
    
    

    public static void main(String[] args) throws IOException {
        //initialize
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        Code solver = new Code();
        solver.solve(in, out);
        out.flush();
        out.close();
    }


    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;

        private InputReader(InputStream stream) {
            this.stream = stream;
        }

        private int read() {
            if (numChars == -1)
                throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        private String readString() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c))
                    res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        private int readInt() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        private long readLong() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            long res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        private double readDouble() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') {
                if (c == 'e' || c == 'E') {
                    return res * Math.pow(10, readInt());
                }
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') {
                c = read();
                double m = 1;
                while (!isSpaceChar(c)) {
                    if (c == 'e' || c == 'E') {
                        return res * Math.pow(10, readInt());
                    }
                    if (c < '0' || c > '9') {
                        throw new InputMismatchException();
                    }
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }

        private boolean isSpaceChar(int c) {
            if (filter != null)
                return filter.isSpaceChar(c);
            return isWhitespace(c);
        }

        public String next() {
            return readString();
        }


        private static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        private char readCharacter() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            return (char) c;
        }

        public interface SpaceCharFilter {
            boolean isSpaceChar(int ch);
        }
    }

    static class OutputWriter {
        private final PrintWriter writer;

        private OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(
                    outputStream)));
        }

        private OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        private void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0) {
                    writer.print(' ');
                }
                writer.print(objects[i]);
            }
            writer.flush();
        }

        private void printLine(Object... objects) {
            print(objects);
            writer.println();
            writer.flush();
        }

        private void printLine(int i) {
            writer.println(i);
        }


        private void close() {
            writer.close();
        }

        private void flush() {
            writer.flush();
        }


    }

    static class IOUtils {

        private static int[] readIntArray(InputReader in, int size) {
            int[] array = new int[size];
            for (int i = 0; i < size; i++)
                array[i] = in.readInt();
            return array;
        }

        private static long[] readLongArray(InputReader in, int size) {
            long[] array = new long[size];
            for (int i = 0; i < size; i++)
                array[i] = in.readLong();
            return array;
        }

        private static char[] readCharArray(InputReader in, int size) {
            char[] array = new char[size];
            for (int i = 0; i < size; i++)
                array[i] = in.readCharacter();
            return array;
        }

        private static char[][] readTable(InputReader in, int rowCount,
                                          int columnCount) {
            char[][] table = new char[rowCount][];
            for (int i = 0; i < rowCount; i++)
                table[i] = readCharArray(in, columnCount);
            return table;
        }

    }

    static class ArrayUtils {

        private static void fill(int[][] array, int value) {
            for (int[] row : array)
                Arrays.fill(row, value);
        }

    }

    static class MiscUtils {
        private static final int[] DX4 = {1, 0, -1, 0};
        private static final int[] DY4 = {0, -1, 0, 1};

        private static boolean isValidCell(int row, int column, int rowCount,
                                           int columnCount) {
            return row >= 0 && row < rowCount && column >= 0
                    && column < columnCount;
        }

    }
}