c=lambda s:(s*(s+1)//2-(s+1)//2)//2
for _ in range(int(input())):
 N,K=map(int,input().split());p=pow(10,K);t,b=divmod(N-1,p);print((c(t-1)*c(p-1)+(t//2*(c(p-1)-c(p-2-b))))%998244353)