program Suma_czesciowa;
var M, n : integer;
  a, s: Real;
begin
  readln(M);
  s:=1;a:=1;n:=1;
  while(n<M) do
  begin
  a:=a/(2*n);
  s:=s+a;
  n:=n+1;
  end;
  writeln(s);
  readln;
end.

program pierwsze;
const N = 999999;
var i, p : integer;
    prarr: array [2..N] of Integer;
begin
    for i:=2 to N do
        prarr[i] := 1;

    p:=2;
    writeln(p);
    A[p]:=0;
    for i:=2 to N do
    begin
        while (p < N) do
        begin
            p:=p+p;
            A[p]:=0;
        end;
        for j:=p to N do
        begin
            if(A[j] = 1) then
                p:=A[j];
        end;
    end;

    for i:=2 to N do
        if(A[i] <> 0)
            writeln(A[i]);

end.

program modul;
const N=8;
type tablica = array [1..N] of Real;
var A : tablica;
  max, max_mod: real;
  i : integer;
begin
          max:=-1; max_mod:=-1;
          for i:= 1 to N do
          begin
            readln(A[i]);
          end;
        for i:=0 to N do
            begin
                    if (A[i] > max) then
                       max:= A[i];
                    if (abs(A[i]) > max_mod) then
                       max_mod:=abs(A[i]);
            end;

        writeln('Max: ', max);
        writeln('Max modul: ', max_mod);
        readln;
end.

program tablica1;


const N = 7;
type tablica = array [1..N] of Integer;
var A : tablica;
  i, suma : integer;
  sr, ilosc, sparz, najm, sred5, el: integer;
  b,c: double;

begin
      suma:=0; sr:=0;ilosc:=0;sparz:=0;sred5:=0;
      el:=0; b:=0;c:=0;
      writeln('Podaj liczby');
      for i:= 1 to N do
          begin
            readln(A[i]);
          end;
      i:=0;
      najm:=0;
      while(i<=N) do
      begin
        suma:= suma + A[i];
        if(A[i] < 0) then
                begin
                sr:= sr + A[i];
                el:= el + 1;
                end;
        if (el > 0) then
            b := sr / el;
        if ((0 < A[i]) and (A[i] < 10)) then
                ilosc := ilosc + 1;
        if ((A[i] < 10) and (A[i] mod 2 = 0)) then
                sparz:= sparz + A[i];
        el:=0;
        if ((A[i] > -50) and (A[i] < 50)) then
           if(A[i] mod 5 = 0) then
              begin
              sred5 := sred5 + A[i];
              el:= el + 1;
              end;
        if (el > 0) then
           c := sred5 / el;
        if (A[i] >10) then
           begin
            if (A[i] < najm) then
               najm := A[i];
           end;
        i:=i+1;

      end;

      writeln('Suma wartosci tablicy:  ', suma);
      writeln('Srednia wartosc z ujemnych elementów tablicy', b);
      writeln('Ilosc liczb z przedzialu 1-10: ', ilosc);
      writeln('Suma liczb parzystych mniejszych od 10: ', sparz);
      writeln('Najmniejsza liczba nieparzysta wieksza od 10: ', najm);
      writeln('Srednia z liczb podzielnych przez 5 z zakresu <-50,50>: ', sred5);
      readln;
end.