a,b=input().split(",")
l = {'A':'10','B':'11','C':'12','D':'13','E':'14','F':'15'}
a = list(a)
b = int(b)
if b == 16:
for i in range(len(a)):
if a[i].upper() in l:
a[i] = l[a[i].upper()]
a = a[-1::-1]
s = 0
for i in range(len(a)):
s += int(a[i]) * b**i
print(s)
题目的测试样例并没有16进制，不过原理都一样，就都写了
