program z1;
var n,i,s: integer;
begin
write ('n = ');
readln(n);
s:=0;
for i:=1 to n do if i mod 2 = 0 then s:=s+i;
write('s = ',s)
end.
program z1;
var n,i,s: integer;
begin
write ('n = ');
readln(n);
s:=0;
for i:=1 to n do if i mod 2 = 0 then s:=s+i;
write('s = ',s)
end.