def count(st):
    if st<=0:
        return 0
    if st%2==1:
        return count(st-1)+st//2
    sm=st*(st+1)//2
    sm-=st//2
    return sm//2

T=int(input())
for _ in range(T):
    N,K=map(int,input().split())
    N-=1
    nt=N//pow(10,K)
    nb=N%pow(10,K)
    ans=count(nt-1)*count(pow(10,K)-1)
    ls=nt//2
    ls*=count(pow(10,K)-1)-count(pow(10,K)-2-nb)
    print((ans+ls)%998244353)