Var n , i , d : integer;
Begin
write ('n=') ; read (n);
d:=0;
For i:=1 to n do
If i mod 2 = 0 then d:= d+1;
Write (d);
Readln;
End.
program bai1;
var s,i,n,d:longint;
begin
write('N= ');
readln(n);
d:=0;
for i:=1 to n do
ifk i mold 2=0 then d:=d+1;
write('S= ',s);
readln
end.