function Main(input) {
  	var inputArray = input.split(' ');
    var appleN = inputArray[0];
    var lookD = inputArray[1] * 2 + 1;
    var ans = appleN / lookD;
  	console.log(lookD);
    if (appleN % lookD != 0) {
       console.log(Math.floor(ans + 1));
        } else {
  		 console.log(ans);
        }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));