PTA (daily question) 7-72 calculate the cumulative sum

Enter two integers n and a, Sum up S=a+aa+aaa+…+aa…a（n individual a） It's worth .
for example , When n=5,a=2 when ,S=2+22+222+2222+22222=24690.

Input format :
There are multiple sets of test data , Processing to the end of the file . Enter two integers for each set of tests n and a（1≤n,a<10）.

Output format :
For each group of tests , Output a+aa+aaa+…+aa…a（n individual a） It's worth .

sample input :

5 3
8 6

sample output :

37035
74074068

Code ：

import math

try:
    while True:
        n, a = map(int,input().split())
        result = 0
        k = 0
        for i in range(n):
            k += a*int(math.pow(10, i))
            result += k
        print(result)
except EOFError:
    pass