program ex9;
uses crt;
var
m:string; bo:boolean; j,i:integer; a:array[1..100]of string; x:array[1..2] of integer;
y:array[1..2] of integer; cry:string;

begin
repeat
write('M: '); readln(m);
bo:= true; j:=1;
repeat
if m[j] in ['A'..'Z',' '] then
    j:= j+1
    else
    bo:= false;
until not(bo) or (j> length(m))
until (length(m) mod 2 = 0) and (bo);


for j:= 1 to length(m)div 2 do
begin
    a[j]:= copy(m,1,2);
    delete(m,1,2);
    i:= 1;
    repeat
        if a[j][i] = ' ' then
        begin
        x[i] := 26;
        i:= i +1
        end
        else
        begin
        x[i] := (ord(a[j][i])-ord('A'));
        i:= i+1;
        end;
    until i=3;
    //writeln(a[j],'  ',x[1],'   ',x[2]);
    y[1] := (11*x[1] + 3*x[2]) mod 27;
    y[2] := (7*x[1] + 4*x[2]) mod 27;
    //writeln(a[j],'  ',y[1],'   ',y[2]);
    cry:= '';
    if y[1]+65=91 then
    cry:= cry+' '+chr(y[2]+65)
    else if y[2] +65=91 then
    cry:= cry+chr(y[1]+65)+' '
    else cry:= cry+chr(y[1]+65)+chr(y[2]+65);
    write(cry);
end;
end.