#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long ll;

int main(){
    int n , k;
    cin >> n >> k;
    int ans = 0;
    if(n % 2 == 0){
        if(k % 2 == 0)ans = min(n / 2 , k + 1);
        else ans = min(n / 2 , ((k + 1) / 2) * 2);
    }else if(n % 2 == 1){
        if(k % 2 == 0)ans = min(n , k + 1);
        else ans = min(n , ((k + 1) / 2) * 2);
    }
    cout << ans << endl;
    return 0;
}