To find this cache, gather the info at the posted coords.
Cache is located at N 38° 37.ABC W 121° 16.XYZ
At the posted coords you will find a County Code. We wil call
that H.IJ.KLM.
You will also find an Emergency Number. We will call that
NOP-QRST
A= O
B= T minus L
C= P
X= O minus K
Y= P plus J minus R
Z= Q plus how long you can park.
N checksum=20 W checksum=19