program bai1;

uses crt;

var i,n,Z,T,gt:integer;S:real;

begin

write('nhap n: ');readln(n);

{a}

begin

for i:=1 to n do S:=S+i;

write('tong S la: ',S:4:2);

{b}

for i:=1 to n do S:=S+1/i;

writeln('tong S la: ',S:4:2);

{c}

for i:=1 to n do S:=S+i*i;

writeln('tong S la: ',S:4:2);

{d}

for i:= 1 to n do S:=S+1/i*i;

writeln('tong S la: ',S:4:2);

{e}

for i:= 1 to n do S:=S+1/(1+i);

writeln('tong S la: ',s:4:2);

{f}

for i:=1 to n do S:=S+1/(i*(S*i));

writeln('tong S la: ',S:4:2);

end;

{g}

for i:=1 to n do

gt:gt*i

S:=S*(1+1/i*i);

writeln('tong S la: ',s:4:2);

{h}

for i:=1 to n do S:=S*(1/i*i);

writeln('tich S la: ',S:4:2);

readln;

end.

   

program bai1phani;

uses crt;

var i,n,Z,T,S:integer;

begin

write('nhap n: ');readln(n);

for i:=1 to n do

if i mod 2=0 then S:=S+1+i;

if i mod 2=1 then Z:=Z-i;

T:=Z+S;

write('tong la: ',T);

readln;

end.