on my property title deeds the term ( party fences) can someone explain what in law,

[magnum]

this means. thanks? my understanding is that i am 50% responsible for the cost off maintaining or replacing the fencing, on either side of my property, but my neighbour on the left says im, 100% responsible for the fence on my left, while my other neighbour on the right, says im 50% responsible for the fence on the right. i appreciate any advice you can give. thanks. ps. the neighbour on the left, is what you would class as a neighbour from hell.