#include<bits/stdc++.h>

#define pb push_back
#define mp make_pair
#define fi first
#define se second

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

template <typename T> bool chkmax(T &x,T y){return x<y?x=y,true:false;}
template <typename T> bool chkmin(T &x,T y){return x>y?x=y,true:false;}

int readint(){
    int x=0,f=1; char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}

const int cys=998244353,N=10000000;
int n,c;
ll a[10000005],ds[10000005];

ll qpow(ll x,ll p){
    ll ret=1;
    for(;p;p>>=1,x=x*x%cys) if(p&1) ret=ret*x%cys;
    return ret;
}

int main(){
    int T=readint();
    ds[1]=1;
    for(int i=2;i<=N;i++) ds[i]=(cys-cys/i)*ds[cys%i]%cys;
    while(T--){
        n=readint(); c=readint();
        a[0]=1;
        a[1]=(c+c+2)%cys;
        ll tmp=1ll*(c+c)*(c+c)%cys,ans=a[1];
        for(int i=2;i<=n;i++){
            a[i]=(a[i-1]*(c+c+2)%cys*(i+i-1)-tmp*(i-1)%cys*a[i-2])%cys;
            if(a[i]<0) a[i]+=cys;
            a[i]=a[i]*ds[i]%cys;
            ans^=a[i];
        }
        printf("%lld\n",ans);
    }
    return 0;
}