Assume we have a direct-mapped cache. The cache size is 2^n blocks (thus n bits are used for the index), and the block size is 2^m words (2^(m+2) bytes). Assume we have 32-bit addresses. What is the size (the number of bits) of each tag field? What is the total number of bits needed for this direct-mapped cache, including valid field, tag field, and data field?