Formula Field Unable to Process Past \

I am trying to create a formula text field and keeping getting an error saying that there are characters outside of the formula.  I am trying to create a file path to pass through Zapier to our cloud server.  Here is the formula:

List("", 
[Term Slot - Term Awards: Grant - Program Year - Fiscal Year],
"\Year Long\", 
[Common Person ID# - Current Member Term: Term Award - Grant Name], 
"\", 
[Term Slot - Person - Contact: Legal Last Name], 
", ", 
[Term Slot - Person - Contact: Legal First Name],
 "\", 
[Term Slot - Person - Contact: Legal Last Name], 
", ", 
[Term Slot - Person - Contact: Legal First Name], 
" PRU ", 
Case([Email Subject],"January", "January","February", "February","March", "March","April", "April","May", "May","June", "June","July", "July","August", "August","September", "September", "October", "October","November", "November","December", "December"),
".pdf")