var i,n,x:integer;a:array [1..100] of integer;beginwrite('Введите N: ');readln(n);for i:=0 to n dox:=x+i;write(x);end.
var i,n,x:integer;
a:array [1..100] of integer;
begin
write('Введите N: ');
readln(n);
for i:=0 to n do
x:=x+i;
write(x);
end.