\(C=\frac{1}{3}+\frac{-3}{4}+\frac{3}{5}+\frac{1}{57}+\frac{-1}{36}+\frac{1}{15}+\frac{-2}{9}\)
\(=\left(\frac{1}{3}+\frac{3}{5}+\frac{1}{15}\right)+\left(\frac{-3}{4}+\frac{-2}{9}+\frac{-1}{36}\right)+\frac{1}{57}\)
\(=\frac{5+9+1}{15}+\frac{\left(-27\right)+\left(-8\right)+\left(-1\right)}{36}+\frac{1}{57}\)
\(=\frac{15}{15}+\frac{-36}{36}+\frac{1}{57}=1-1+\frac{1}{57}=\frac{1}{57}\)