sub v {
  ord($_[0]) - ord('A');
}

print v('I')*26 + v('V'), "\n";

##</code><code>##

shell$ perl ./iv65536
229
shell$

##</code><code>##

print (v('I')+1)*26 + v('V'), "\n";

##</code><code>##

shell$ perl ./iv65536
9shell$