function main(input){
  var Gusu = 0;//偶数の個数
  var Kisu = 0;//奇数の個数
  if(input > 0){
  	if(input % 2 == 0){
      Gusu = input / 2;
      Kisu = Gusu;
  	}
    if(input % 2 == 1){
      Gusu = input / 2;
      Kisu = Gusu+1;
  	}
  }
  console.log("%d",parseFloat(Kisu/input));
}

main(require("fs").readFileSync("/dev/stdin", "utf8"));