Q=int(input())
for _ in range(Q):
  N,K=map(int,input().split())
  N-=1
  result=0
  mod=998244353
  M=10**K
  p=M//2
  w=M*p-p*(1+p)
  t=N//M
  if t>=2:
    s=t//2
    w*=t*s-s*(s+1)
    w%=mod
    result+=w
    result%=mod
    pos=N%M
    l=0
    r=p
    while True:
      m=(l+r+1)//2
      score=M-2*m
      if score>pos:
        l=m
      else:
        r=m-1
      if l==r:
        break
    q=0
    q+=l*(pos+1)
    q%=mod
    count=p-l
    q+=M*count
    q%=mod
    q-=count*(l+1+p)
    q%=mod
    result+=q*s
    result%=mod
  print(result)