## 1. Bark

One smart dog knew how to count in the quaternary number system. She conveyed zero in her dog language with the sound "o", one with the sound "u", two with the sound "v", and finally, three with the sound "a". What number, in this case, did her bark "ouavoouav" represent?
1. Ouoouo $=\left(2 \cdot 4^{0}\right)+\left(3 \cdot 4^{1}\right)+\left(1 \cdot 4^{2}\right)+\left(0 \cdot 4^{3}\right)+\left(2 \cdot 4^{4}\right)+$ $+\left(3 \cdot 4^{5}\right)+\left(1 \cdot 4^{6}\right)+\left(0 \cdot 4^{7}\right)=2+12+16+0+512+3072+0+$ $+4096+0=7710$.