Program BTT;
Uses crt;
Var n: longint;
Function ktra(b: longint): boolean;
Var k: byte;
Begin
k:=b mod 10;
b:=b div 10;
While b<>0 do
If b mod 10 <> k then exit(false)
Else b:=b div 10;
exit(true);
End;
Begin
Clrscr;
Write('Nhap so bat ki: '); Readln(n);
If ktra(n) then Write('Phai')
Else Write('Khong phai');
Readln
End.