uses crt;
var k,i:longint;
S1,S2:real;
begin
clrscr;
write('Nhap so cuoi cung cua day so: ');readln(n);
S1:=0;S2:=0;
for i:= 1 to n do S1:=S1+(1/i);
for k:=1 to n do
if k mod 2=1 then S2:=S2+(1/i);
writeln('Cau a: S1=',S1:0:2);
writeln('Cau b: S2=',S2:0:2);
readln;
end.