#include <bits/stdc++.h> using namespace std; const int mod=998244353,maxn=1e7+5; inline int read() { int x=0; char ch=getchar(); while(ch<'0'||ch>'9') ch=getchar(); while(ch>='0'&&ch<='9') x=(x<<3)+(x<<1)+(ch^48),ch=getchar(); return x; } inline int qp(int a, int b) { int ans=1; while(b) { if(b&1) ans=ans*a%mod; a=a*a%mod,b>>=1; } return ans; } int fac[10000005]= {1},inv[10000005]= {1},t,n,m; int main() { for(int i=1; i<=maxn; i++) fac[i]=1ll*fac[i-1]*i%mod; inv[maxn]=qp(fac[maxn],mod-2); for(int i=maxn-1; i; i--) inv[i]=1ll*inv[i+1]*(i+1)%mod; t=read(); while(t--) { m=read(),n=read(); if(n<m-1) puts("0"); else printf("%d\n",1ll*fac[n]%mod*fac[n+1]%mod*inv[n-m+1]%mod); } return 0; }