Euclid's C-Finder

{1}, {t}: Add {e}. Euclid's C-Finder does not untap
during your next untap step.
ARCHIMEDES Protocol — At the beginning of
combat on your turn, you may tap this card and
another card you control with ARCHIMEDES
Protocol; if you do, remove all {e} and destroy
each nonland permanent you don't control with
mana value less than the total {e} you removed.
A2 + B2 = C2