Compare and print last column in a file

Question

I have a file

(n34)); 1
Z(n2)); 1
(n52)); 2
(n35)); 3
(n67)); 3
(n19)); 4
(n68)); 4
(n20)); 5
(n36)); 5
(n53)); 5
(n69)); 5
N(n3)); 5
(n54)); 6
(n70)); 7
N(n4