import sys

sys.setrecursionlimit(10 ** 8)

input = sys.stdin.readline


def main():
    N = int(input())
    K = int(input())

    nstr = str(N)

    nl = len(str(N))

    dp = [[[0 for _ in range(nl + 1)] for _ in range(2)] for _ in range(nl + 1)]
    dp[0][0][0] = 1

    for i in range(nl):
        max_digit = int(nstr[i])
        for smaller in range(2):
            for j in range(nl):
                range_digit = 9
                # range_digit = 9 if smaller else max_digit
                if not smaller:
                    range_digit = max_digit
                for x in range(range_digit + 1):
                    if x != 0:
                        if smaller == 1:
                            dp[i + 1][smaller][j + 1] += dp[i][smaller][j]
                        else:
                            if x < max_digit:
                                dp[i + 1][1][j + 1] += dp[i][smaller][j]
                            else:
                                dp[i + 1][0][j + 1] += dp[i][smaller][j]
                    else:
                        if smaller == 1:
                            dp[i + 1][smaller][j] += dp[i][smaller][j]
                        else:
                            if x < max_digit:
                                dp[i + 1][1][j] += dp[i][smaller][j]
                            else:
                                dp[i + 1][0][j] += dp[i][smaller][j]

    ans = 0
    print(dp[nl][1][K])


if __name__ == '__main__':
    main()
