uses crt;
var n:longint;
begin
clrscr;
write('Nhap so tien khach hang mua: ');readln(n);
if n<0 then write('vo nghiem')
else
begin
if n>=100000 then n:=trunc((n/100)*70)
else n:=trunc((n/100)*90);
write('So tien sau khi giam gia: ',n);
end;
readln;
end.