318A.cpp

#include<iostream>
using namespace std;

int main(){
    long long int a,b,c;
    cin >> a >> b;
    if(a%2 == 0){
        c = a/2;
    }
    else{
        c = (a+1)/2;
    }
    if(b <= c){
        cout << (b*2) - 1 << endl;
    }
    else{
        cout << (b-c) * 2 << endl;
    }
}