This is the bonus mystery cache for the traditional cache on the Millenium Bridge .
Your adventure starts here: N 42° 26.697 E 019° 15.577
The amount of poles above the benches, connecting the bridge, on these coordinates, is the value of A.
To get the value of B, you'll need to do a bit of research.
The value of B equals the year the construction of the bridge started.
Final coordinates:
N 42° (A+14).(B-1275) E 019° (A*2-9).(A*37+4)