package main

import (
    "bufio"
    "fmt"
    "os"
    "strconv"
)

func main() {
    var A, B int;
    fmt.Scanf("%d %d", &A, &B)
    if A < B {
        Print(B-2)
    } else {
        Print(2000000000-B-1)
    }
}

func Print(x ...interface{}){
    l := len(x) + 1
    for ii, vi := range x {
        fmt.Print(vi)
        if ii == l {
            fmt.Print("\n")
        } else {
            fmt.Print(" ")
        }
    }
}
var sc = bufio.NewScanner(os.Stdin)
func Input() string {
    sc.Scan()
    return sc.Text()
}
func InputInt() int {
    sc.Scan()
    i, e := strconv.Atoi(sc.Text())
    if e != nil {panic(e)}
    return i
}
func BinCount(x int) int {
    s := fmt.Sprintf("%b", x)
    c := 0
    for _, i := range s {
        if i == '1' {c += 1}
    }
    return c
}