program zamena;
uses crt;
var
txt: string;
i, k: integer;
word: boolean;
begin
clrscr;
writeln('Vvedite text');
readln(txt);
k := 1;
for i := 1 to Length(txt) do
begin
if txt[i] in [' ', '.', ',', '!', '?', ';', ':'] then
begin
k := 1;
write(txt[i]);
end
else
begin
if (txt[i] = 'a') and (k mod 2 = 0) then
write('e')
else
if (txt[i] = 'b') and (k mod 2 = 1) then
write('ak')
else
write(txt[i]);
k := k + 1;
end;
end;
readkey;
end.