var H: real;
N, i: integer;
begin
H := 0;
readln(N);
for i := 1 to N do
H := H + 1/i;
writeln(H:6:4)
end.
var H: real;
N, i: integer;
begin
H := 0;
readln(N);
for i := 1 to N do
H := H + 1/i;
writeln(H:6:4)
end.