Chromium has an atomic mass of 51.9961 u and consists of four isotopes, Cr50, Cr52, Cr53, and Cr54. The Cr52 isotope has a natural abundance of 83.79% and an atomic mass of 51.9405 u. The Cr54 isotope has a natural abundance of 2.37% and an atomic mass of 53.9389 u. The natural abundances of the Cr50 and Cr53 isotopes exist in a ratio of 1:0.4579, and the Cr50 isotope has an atomic mass of 49.9460 u. Determine the atomic mass of the Cr53 isotope.