#include <bits/stdc++.h>

using namespace std;
#define int long long
const int p=998244353;
int po(int a,int b) {if(b==0) return 1; if(b==1) return a; if(b%2==0) {int u=po(a,b/2);return (u*u)%p;} else {int u=po(a,b-1);return (a*u)%p;}}
int inv(int x) {return po(x,p-2);}
int32_t main()
{
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int h=(1<<12)*7*17;
    int t;cin>>t;while(t--)
    {
    int a,n;cin>>a>>n;
    int res=0;
    for(int i=0;i<h;++i)
    {
        if(i>=n) continue;
        int o=(n-1-i)/h+1;
        int l=i*i;int r=i*i+o*i*2*h;
        int step=2*i*h;int u=po(a,step);
        if(u!=1) {int inva=inv(u-1);res+=(po(a,r)-po(a,l))*inva;res%=p;}
        else {res+=po(a,l)*o;res%=p;}
    }
    cout<<(res%p+p)%p<<'\n';
    }
    return 0;
}