F to C BF Program

Input a temperature and it converts it to Celsius. It's in a cell (changes depending upon the length of input) but I'm not sure how to get convert the number to ASCII characters to output with ".". I'm stumped!

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----------------------------------<[<++++++++++>-]<[->>+<<][->>+<<]>>>]++++++[<-
---->-]<--[<++++++++++>-]++++++++++++++++++<[>[->+>+<<]>[-<<-[>]>>>[<[>>>-<<<[-]
]>>]<<]>>>+<<[-<<+>>]<<<]>[-]>>>>[-<<<<<+>>>>>]<<<<<