// parameter "input" gets all data
function Main(input) {
  	var output = function (input) {
      if (input === 1) return 1 / 1;
      if (input%2 === 0) {
        return (input/2) / input;
      } else {
        return ((input+1)/2) / input;
      }
    }
	//output
	console.log(output(input));
}
// Don't edit this line!
Main(require("fs").readFileSync("/dev/stdin", "utf8"));