program chusolonnhat;
uses crt;
var n,max,m:longint;
begin
clrscr;
write('Nhap n: '); readln(n);
m:=n;
max:=m mod 10;
m:=m div 10;
while m<>0 do
begin
if m mod 10>max then max:=m mod 10;
m:=m div 10;
end;
writeln('Chu so lon nhat cua ',n,' la: ',max);
readln
end.