Program ChuoiChuan;
Var s, p : String;
i, l, r : Byte;
Begin
Write('Nhap s:');
Readln(s);
p := '';
l := 1;
r := Length(s);
While (l <= r) And (s[l] = ' ') Do
Inc(l);
While (r > l) And (s[r] = ' ') Do
Dec(r);
For i := l To r Do
If (s[i] <> ' ') Or (p[Length(p)] <> ' ') Then p := p + s[i];
Writeln( 'Chuoi da chuan hoa:', p);
End.