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