解法1：

while True:
    try:
        number = input()
        n = len(number)
        dic = {'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}
        final = 0
        for i in range(2,n):
            final += dic[number[i]]*(16**(n-i-1))
        print(final)
    except:
        break

解法2：

while True:
    try:
        print(int(input(),16))

    except:
        break