2,3.
Uses crt;
Var s: string;
i: longint;
Begin
Clrscr;
Write('Nhap xau s'); Readln(s);
While pos(s,' ')<>0 then delete(s,pos(s,' '),1); {Xóa các ký tự trắng thừa}
If s[1]=' ' then delete(s,1,1);
If s[length(s)]=' ' then delete(s,length(s),1);
Writeln('Do dai thuc cua xau:',length(s))...