#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define maxn 1000006
bool mark[1000006+5];
ll isprime[maxn+5],psize=0;


void sieve()
{
    mark[0]=true;
    mark[1]=true;
    for(ll i=2;i*i<=maxn;i++)
    {
        if(mark[i]==false)
        {
            for(ll j=i*i;j<=maxn;j+=i)
                mark[j]=true;
        }
    }

    for(ll i=2;i<=maxn;i++)
    {
        if(mark[i]==false)
            isprime[psize++]=i;
    }
}

int main()
{
   sieve();
   ll t,i,j,k,low,high,a,b,c,d,e,f;
   cin>>t;
   while(t--)
   {
       cin>>low>>high;

       vector<ll>v;
       for(i=0;i<=psize;i++)
       {
           if(isprime[i]>=low && isprime[i]<=high)
           {
               v.push_back(isprime[i]);
           }
           if(isprime[i]>high)
              break;
       }
       if(v.size()<2)
       {
           cout<<"No jumping champion"<<endl;
           continue;
       }
       map<ll,ll>m;
       for(i=1;i<v.size();i++)
       {
           a=v[i]-v[i-1];
           m[a]++;
       }
       vector<pair<ll,ll> >vp;
       for(auto i: m)
       {
           vp.push_back(make_pair(i.second,i.first));
       }
       sort(vp.rbegin(),vp.rend());

       if(vp.size()==1)
          cout<<"The jumping champion is "<<vp[0].second<<endl;
       else if(vp.size()>1)
       {
           if(vp[0].first>vp[1].first)
              cout<<"The jumping champion is "<<vp[0].second<<endl;
           else
            cout<<"No jumping champion"<<endl;
       }
       else
        cout<<"No jumping champion"<<endl;
   }
   return 0;
}