FWIW, "4 - 2" is explained earlier in the file: // The "-2" is included because the for-loop will // always increment by 2. In this case, we want to // s

FWIW, "4 - 2" is explained earlier in the file: // The "-2" is included because the for-loop will // always increment by 2. In this case, we want to // skip an extra 2 bytes since we used 4 bytes // of input. i += 4 - 2;