One day Misha and Andrew were playing a very simple game. First, each player chooses an integer in the range from 1 to n. Let's assume that Misha chose number m, and Andrew chose number a.

Then, by using a random generator they choose a random integer c in the range between 1 and n (any integer from 1 to n is chosen with the same probability), after which the winner is the player, whose number was closer to c. The boys agreed that if m and a are located on the same distance from c, Misha wins.

Andrew wants to win very much, so he asks you to help him. You know the number selected by Misha, and number n. You need to determine which value of a Andrew must choose, so that the probability of his victory is the highest possible.

More formally, you need to find such integer a (1 ≤ a ≤ n), that the probability that <image> is maximal, where c is the equiprobably chosen integer from 1 to n (inclusive).

Input

The first line contains two integers n and m (1 ≤ m ≤ n ≤ 109) — the range of numbers in the game, and the number selected by Misha respectively.

Output

Print a single number — such value a, that probability that Andrew wins is the highest. If there are multiple such values, print the minimum of them.

Examples

Input

3 1


Output

2

Input

4 3


Output

2

Note

In the first sample test: Andrew wins if c is equal to 2 or 3. The probability that Andrew wins is 2 / 3. If Andrew chooses a = 3, the probability of winning will be 1 / 3. If a = 1, the probability of winning is 0.

In the second sample test: Andrew wins if c is equal to 1 and 2. The probability that Andrew wins is 1 / 2. For other choices of a the probability of winning is less.
import java.io.*;
import java.util.*;
import java.nio.charset.StandardCharsets;
// import java.math.BigInteger;

public class B {
    static Writer wr;

    public static void main(String[] args) throws Exception {
        // long startTime = System.nanoTime();

        // String testString = "";
        // InputStream stream = new ByteArrayInputStream(testString.getBytes(StandardCharsets.UTF_8));
        // Reader in = new Reader(stream);

        Reader in = new Reader();
        BufferedWriter out = new BufferedWriter(new OutputStreamWriter(System.out));
        
        wr = new Writer();

        /* Precomputation */


        // long elapsedTime = System.nanoTime() - startTime;
        // double seconds = (double)elapsedTime / 1000000000.0;
        // wr.writeRedLn(seconds);

        /* Input */
        int N = in.nextInt();
        int M = in.nextInt();

        int d = N-M;

        int ans = 0;
        if(d>=M) {
            ans = M+1;
        }
        else {
            ans = M-1;
        }

        if(ans==0) ans = 1;

        out.write(ans + "\n");    

        
        out.flush();
    }
}



class Writer {
    public void writeRedLn(Object x) { writeRedLn(x+""); }
    public void writeBlueLn(Object x) { writeBlueLn(x+""); }
    public void writeGreenLn(Object x) { writeGreenLn(x+""); }
    public void writePinkLn(Object x) { writePinkLn(x+""); }
    public void writeRedLn(String x) { System.out.println((char)27 + "[31m" + (char)27 + "[40m" + x + (char)27 + "[0m"); }
    public void writeBlueLn(String x) { System.out.println((char)27 + "[34m" + (char)27 + "[3m" + x + (char)27 + "[0m"); }
    public void writeGreenLn(String x) { System.out.println((char)27 + "[32m" + (char)27 + "[3m" + x + (char)27 + "[0m"); }
    public void writePinkLn(String x) { System.out.println((char)27 + "[30m" + (char)27 + "[45m" + x + (char)27 + "[0m"); }
    public void writeRed(String x) { System.out.print((char)27 + "[31m" + (char)27 + "[40m" + x + (char)27 + "[0m"); }
    public void writeBlue(String x) { System.out.print((char)27 + "[34m" + (char)27 + "[3m" + x + (char)27 + "[0m"); }
    public void writeGreen(String x) { System.out.print((char)27 + "[32m" + (char)27 + "[3m" + x + (char)27 + "[0m"); }
    public void writePink(String x) { System.out.print((char)27 + "[30m" + (char)27 + "[45m" + x + (char)27 + "[0m"); }
}


class Reader {
    public int LINE_LIMIT = -1;
    final private int BUFFER_SIZE = 1 << 16;private DataInputStream din;private byte[] buffer;private int bufferPointer, bytesRead;
    public Reader(){din=new DataInputStream(System.in);buffer=new byte[BUFFER_SIZE];bufferPointer=bytesRead=0;}
    public Reader(InputStream stream){din=new DataInputStream(stream);buffer=new byte[BUFFER_SIZE];bufferPointer=bytesRead=0;}
    public int[] ni_array(int N) throws IOException { int[] ans = new int[N]; for(int i=0;i<N;i++) { ans[i] = nextInt(); } return ans; }
    public String readLineUtil()throws IOException{byte[] buf=new byte[Math.max(400024,LINE_LIMIT)];int cnt=0,c;
        while((c=read())!=-1){if(c=='\n')break;buf[cnt++]=(byte)c;}return new String(buf,0,cnt);}
    public String readLine() throws IOException{ String line = readLineUtil().trim(); while(line.length()==0) line = readLineUtil().trim(); return line; }
    public char nextChar()throws IOException{byte c=read();while(c<=' ')c=read();return (char)c;}
    public int nextInt()throws IOException{int ret=0;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');
        if(neg)c=read();do{ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');if(neg)return -ret;return ret;} 
    public long nextLong()throws IOException{long ret=0;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');
        if(neg)c=read();do{ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');if(neg)return -ret;return ret;}
    public double nextDouble()throws IOException{double ret=0,div=1;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');if(neg)c = read();do {ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');
        if(c=='.')while((c=read())>='0'&&c<='9')ret+=(c-'0')/(div*=10);if(neg)return -ret;return ret;}
    private void fillBuffer()throws IOException{bytesRead=din.read(buffer,bufferPointer=0,BUFFER_SIZE);if(bytesRead==-1)buffer[0]=-1;}
    private byte read()throws IOException{if(bufferPointer==bytesRead)fillBuffer();return buffer[bufferPointer++];}
    public void close()throws IOException{if(din==null) return;din.close();}
}
