var a, b, i, j, n : longint;
c : real;
begin
readln(n);
a := 1;
for i := 1 to n do
begin
a := a * i;
c := c + (1 / a);
end;
writeln(c : 1 : 0);
end.
var a, b, i, j, n : longint;
c : real;
begin
readln(n);
a := 1;
for i := 1 to n do
begin
a := a * i;
c := c + (1 / a);
end;
writeln(c : 1 : 0);
end.