题解 | #进制转换#

import sys

hex: str = ''

hex_dict = {'A': 10, 'B': 11, 'C': 12, 'D': 13, 'E': 14, 'F': 15}

for line in sys.stdin:
    hex = line.strip()[2:]

length = len(hex)
digit = 0
for i in range(length):
    exp = 16 ** (length - 1 - i)
    if hex[i].isnumeric():
        digit += int(hex[i]) * exp
    else:
        digit += hex_dict[hex[i]] * exp
        
print(digit)