import sys input = sys.stdin.readline mod=998244353 from collections import Counter FACT=[1] for i in range(1,2*10**6+1): FACT.append(FACT[-1]*i%mod) FACT_INV=[pow(FACT[-1],mod-2,mod)] for i in range(2*10**6,0,-1): FACT_INV.append(FACT_INV[-1]*i%mod) FACT_INV.reverse() def Combi(a,b): if 0<=b<=a: return FACT[a]*FACT_INV[b]%mod*FACT_INV[a-b]%mod else: return 0 MAX=10**6+10 # 使いたい最大値を指定 # Sieve[i]で、iの最も小さい約数を返す。 Sieve=[i for i in range(MAX)] for i in range(2,MAX): if Sieve[i]!=i: continue for j in range(i,MAX,i): if Sieve[j]==j: Sieve[j]=i # 素因数分解 def fact(x): D=dict() while x!=1: k=Sieve[x] if k in D: D[k]+=1 else: D[k]=1 x//=k return D # 約数列挙 def faclist(x): LIST=[1] while x!=1: k=Sieve[x] count=0 while x%k==0: count+=1 x//=k LIST2=[] for l in LIST: for i in range(1,count+1): LIST2.append(l*k**i) LIST+=LIST2 return LIST Q=int(input()) C=Counter() NOW=0 for i in range(Q): a,b=map(int,input().split()) F=fact(a) for f in F: C[f]+=F[f] NOW+=F[f] print(Combi(NOW-1,b-1))