题解 | 进制转换

import sys

a = input()
hex =a[2:]

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



aplha="ABCDEF"
aplhaLen=len(hex)
num=0
for i in hex:
    if i in aplha:
        num += int(h[str(i)])*16**(aplhaLen-1)
        aplhaLen-=1
    else:
        num += int(i)*16**(aplhaLen-1)
        aplhaLen-=1

print(num)