using System;

namespace PiELn2 {
  public class PiELn2 {
    private static decimal Fact(int n) {
      decimal factorial = 1;

      for (int i = 2; i <= n; i++) {
        factorial = factorial * i;
      }
      return factorial;
    }

    public static void calc(out decimal pi, out decimal e, out decimal ln2) {
      pi = 0;
      e = 0;
      ln2 = 0;

      for (int k = 0; k < 15; k++) {
        pi = pi + (1 / (decimal)Math.Pow(16, k)) * (decimal.Divide(4, 8 * k + 1) - decimal.Divide(2, 8 * k + 4) -
          decimal.Divide(1, 8 * k + 5) - decimal.Divide(1, 8 * k + 6));
      }
      pi = Math.Round(pi, 15);

      for (int n = 1; n <= 18; n++) {
        e = decimal.Add(e, decimal.Divide(1, Fact(n)));
      }
      e = Math.Round(e + 1, 15);

      for (int n = 2; n < 50; n++) {
        ln2 = decimal.Add(ln2, decimal.Divide(1, decimal.Multiply(n, (decimal)Math.Pow(2, n))));
      }
      ln2 = Math.Round(decimal.Add(ln2, decimal.Divide(1, 2)), 15);
    }
  }
}