icons = set()
for map_id in map_headers:
    if map_id in [0x0b, 0x45, 0x4b, 0x4e, 0x69, 0x6a, 0x6b, 0x6d, 0x6e, 0x6f, 0x70, 0x72, 0x73, 0x74, 0x75, 0xad, 0xcc, 0xcd, 0xce, 0xe7, 0xed, 0xee, 0xf1, 0xf2, 0xf3, 0xf4]: continue #skip
    map = map_headers[map_id]
    for thing_id in map["object_data"]["things"]:
        thing = map["object_data"]["things"][thing_id]
        icons.add(thing["picture_number"])

print len(icons) #66

icons = [0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x33, 0x34, 0x35, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x45, 0x48]