ENCODE PASCAL

var     m:string;

function s(m:string):longint;
var     kq,i,x:longint;
begin
    kq:=0;
    for i:=1 to 10 do
    begin
        x:=ord(m[i])-48;
        kq:=kq+i*x;
    end;
    exit(kq);
end;

procedure giai;
var     p:longint;
        c:char;
begin
    p:=pos('?',m);
    for c:= '0' to '9' do
    begin
        m[p]:=c;
        if s(m) mod 11 = 0 then
        begin
            write(c);
            exit;
        end;
    end;
end;

begin
        assign(input,'encode.inp');reset(input);
        assign(output,'encode.out');rewrite(output);
        readln(m);
        giai;
end.