#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, k;
  cin >> n;
  cin >> k;
  if (n % 2 == 0) {
    if (k <= (n / 2))
      cout << 2 * (k - 1) + 1;
    else {
      k = k - (n / 2);
      cout << 2 * k;
    }
  } else {
    if (k <= (n + 1) / 2)
      cout << 2 * (k - 1) + 1;
    else {
      k = k - (n + 1) / 2;
      cout << 2 * k;
    }
  }
}
