A mathematical problem: given that AB is the opposite number, CD is reciprocal, e is the largest negative integer, how much is a + B + CD + e?

A mathematical problem: given that AB is the opposite number, CD is reciprocal, e is the largest negative integer, how much is a + B + CD + e?

AB is opposite to each other
a+b=0
CD is reciprocal to each other
cd=1
E is the largest negative integer
e=-1
So, a + B + CD + e = 0