#include<bits/stdc++.h>
using namespace std;
constexpr int mod=998244353,N=1e5+5;
inline int qpow(int a,int b){
    int ans=1;
    while(b){
        if(b&1) ans=ans*1ll*a%mod;
        a=a*1ll*a%mod,b>>=1;
    }
    return ans;
}
int fac[N],inv[N];
int main(){
    ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
    int T;cin>>T;
    for(int i=fac[0]=1;i<=N-4;i++)fac[i]=fac[i-1]*1ll*i%mod;
    inv[N-4]=qpow(fac[N-4],mod-2);
    for(int i=N-4;i>=1;i--) inv[i-1]=inv[i]*1ll*i%mod;
    while(T--){
        int n;long long k;
        cin>>n>>k;
        int l=0,r=(n+1)/2;
        while(l<r){
            int mid=l+r+1>>1;
            if(mid*1ll*(n+1-mid)<=k)l=mid;
            else r=mid-1;
        }
        if(l*1ll*(n+1-l)==k) cout<<fac[n+1]*1ll*inv[l]%mod*inv[n+1-l]%mod*(l==n+1-l?inv[2]:1)%mod<<'\n';
        else cout<<"0\n";
    }
}