import sys
input = sys.stdin.readline
N, K = map(int, input().split())
if K==1:
    print(0)
    exit()
K-=1
dp = [0 for _ in range(20)]
i = 0
while N>0:
    a = N%10
    dp[i] = a+1
    N//=10
    i+=1
#print(dp)
ans = []
i = 0
while K>0:
    a = K%dp[i]
    ans.append(a)
    K//=dp[i]
    i+=1
ans = ans[::-1]
print("".join(map(str, ans)))