{$APPTYPE CONSOLE}
uses
SysUtils;
Var
C:string;
i:integer;
begin
Read(C);
if Length(C) mod 4 <> 0 then
For i:= 1 to 4-Length(C) mod 4 do
C:='0'+C;
For i:= 1 to Length(C) div 4 do
Case StrToInt(C[4*i-3]+C[4*i-2]+C[4*i-1]+C[4*i]) of
0000:Write(0);
0001:Write(1);
0010:Write(2);
0011:Write(3);
0100:Write(4);
0101:Write(5);
0110:Write(6);
0111:Write(7);
1000:Write(8);
1001:Write(9);
1010:Write('A');
1011:Write('B');
1100:Write('C');
1101:Write('D');
1110:Write('E');
1111:Write('F');
End;
ReadLn;
end.