program bt8;
Uses crt;
Var s1,s2:string;
begin
    writeln('Nhap xau thu nhat:');
    Readln(s1);
    Writeln('nhap xau thu hai:');
    Readln(s2);
    Delete(s1,4,5);
    Writeln(s1);
    Insert(s1,s2,4);writeln(s2);
    Readln
End.