题解 | #进制转换# 查表转换

import sys

for line in sys.stdin:
    dict_map = {
        '0': 0,
        '1': 1, '2': 2, '3': 3,
        '4': 4, '5': 5, '6': 6,
        '7': 7, '8': 8, '9': 9,
        'A': 10, 'B': 11, 'C': 12, 
        'D': 13, 'E': 14, 'F': 15
    }
    ans = 0
    num = line.strip()
    num = num[2:]
    base = 1
    for i in range(len(num) - 1, -1, -1):
        ans += base * dict_map[num[i]]
        base = base * 16
    print(ans)