import java.math.BigDecimal; import java.util.Scanner; public class Main { public BigDecimal goldenCoin(double n){ BigDecimal p; if (n >= 990){ p = new BigDecimal("1"); }else { BigDecimal m = new BigDecimal("1"); for (int i = 0; i < n ; i ++){ m = m .multiply (new BigDecimal(Double.toString(990 - i))); m = m.divide(new BigDecimal(Double.toString(1000 - i)), 6, BigDecimal.ROUND_HALF_UP); } p = new BigDecimal(1) .subtract(m) ; } return p; } public static void main(String[] args){ Scanner in = new Scanner(System.in); double n = in.nextDouble(); Main goldenCoin = new Main(); System.out.println(goldenCoin.goldenCoin(n).setScale(6,BigDecimal.ROUND_HALF_UP)); } }