uses crt;
var n,i,t,s:longint;
begin
clrscr;
write('n='); readln(n);
t:=1;
s:=1;
for i:=2 to n do
begin
t:=t+2;
s:=s+t;
end;
writeln(s);
readln;
end.
uses crt;
var n,i,t,s:longint;
begin
clrscr;
write('n='); readln(n);
t:=1;
s:=1;
for i:=2 to n do
begin
t:=t+2;
s:=s+t;
end;
writeln(s);
readln;
end.
var n,i,s:integer;
begin
write('Nhap n: ');
readln(n);
for i:=1 to n do
if i mod 2 <>0 then s:=s+i;
write('Tong ',n,' so tu nhien le: ',s);
end.
var n,i,s:integer;
begin
write('Nhap n: ');
readln(n);
for i:=1 to n do
if i mod 2 <>0 then s:=s+i;
write('Tong ',n,' so tu nhien le: ',s);
end.
var n,i,s:integer;
begin
write('Nhap n: ');
readln(n);
for i:=1 to n do
if i mod 2 <>0 then s:=s+i;
write('Tong ',n,' so tu nhien le: ',s);
end.
Program tinh_tong;
Uses crt;
Var n,t,i,dem:integer;
Begin
Clrscr;
Writeln('hay nhap n');
Readln(n);
t:=0;
i:=0;
Repeat
i:=i+1;
If i mod 2 =0 then
Begin
t:=t+i;
dem:=dem+1;
End;
Until (dem=n);
Write('tong la ',t);
Readln
End.