To principle,
(school),
(city),
(Date),
subject= leave to go Moscow,
Respected Mam,
I am writing this letter to inform you that I want to I want to months of leaf or some important office work of my father in Moscow so why can't I kindly request you to grant me leave for 2 months I I hope you will give me the required months of leave.
Your obediently,
(Name)
Hope this help you.