1.
program mmm;
uses crt;
var n,i,s:longint;
begin
writeln('nhapn =');readln(n);
i:=2;
while i>= n do
begin
s:=s+i;
i:=i+2;
end .
2.
var a:array[1..100] of integer;
n,i:integer;
begin
clrscr;
write('Nhap n: '); readln(n);
for i:=1 to n do
begin
write('a[',i,']: '); readln(a[i]);
end;
for i:=1 to n do
if a[i] mod 2=0 then
write(a[i],' ');
readln;
end.