N = int(input())
K = int(input())
SN = str(N)
LN = list(SN)
keta =len(LN)
Nzer = keta-K
Nsei = K
output = 0
if keta>=K:
    output += comb(keta,K,10**9+7)*9**K
    t = 0
    while K-1-t>=0:
        output -= (9-int(LN[t]))*comb(keta-1-t,K-1-t,10**9+7)*9**(K-1-t)
        t += 1
print(output)