two months M|O|N|TH|S M|AH|N|T|S M|O|N|T|S M|AH|N|TH|SH M|O|N|TH|SH M|AH|N|T|SH M|O|N|T|SH Incubation I|NG|K|Y|U|B|E + I|SH|AX|N IH|NG|K|Y|O|B|E + I|SH|AX|N I|NG|K|Y|O|B|E + I|SH|AX|N IH|NG|K|Y|U|B|A|SH|AX|N I|NG|K|Y|U|B|A|SH|AX|N IH|NG|K|Y|O|B|A|SH|AX|N I|NG|K|Y|O|B|A|SH|AX|N IH|NG|K|Y|U|B|E + I|S|AX|N I|NG|K|Y|U|B|E + I|S|AX|N IH|NG|K|Y|O|B|E + I|S|AX|N I|NG|K|Y|O|B|E + I|S|AX|N IH|NG|K|Y|U|B|A|S|AX|N I|NG|K|Y|U|B|A|S|AX|N IH|NG|K|Y|O|B|A|S|AX|N I|NG|K|Y|O|B|A|S|AX|N period P|I|R|I|AX|D P|IH|R|IH|AX|D P|I|R|IH|AX|D P|IH|R|I|AX|JH P|I|R|I|AX|JH P|IH|R|IH|AX|JH P|I|R|IH|AX|JH