program brainly;
var n, i :integer;
s:real;
begin
s:=1;
Write('Dati n:'); readln(n);
Write('S=',s:2:2,'+');
for i:=1 to n do begin
s:=s+(1/(i*2));
if i=n then
begin
Write('1/',i*2);
end
else begin
Write('1/',i*2, '+');
end;
end;
Writeln();
Writeln('S=',s:2:2);
end.
