题解 | #进制转换#

while True:
    try:
        s = input().strip()[2:]
        N = len(s)

        res = 0
        for i, c in enumerate(s):
            num = 0
            if c.isalpha():
                num = ord(c) - 55
            if c.isdigit():
                num = int(c)
            res += num * (16**(N-i-1))
        print(res)
    except:
        break