#include<bits/stdc++.h>
#define MAX 1000008
using namespace std;
bool flag[MAX];
int primes[MAX];
int cnt,a[2000];
void sieve(int n)
{
cnt=0;
primes[cnt++] = 2;
for(int i=3; i<=n; i+=2)
{
if(flag[i] == 0)
{
primes[cnt++] = i;
if(i <= n/i)
{
for(int j=i*i; j<=n; j+=i*2)
flag[j] = 1;
}
}
}
return ;
}
int main()
{
int n,u,l,pos,c,count,max,k,result,j,i;
sieve(MAX);
cin>>n;
while(n--)
{
pos=0;
cin>>l>>u;
for(int i=0;i<cnt;i++)
{
if(primes[i]>=l)
break;
pos++;
}
memset(a, 0, sizeof(a));
for(j=pos;j<cnt and primes[j+1]<=u;j++)
//a[primes[j+1] - primes[j]]++;
{
a[primes[j+1]-primes[j]]++;
}
count=0, max=0;
for(k=0; k<120; k++)
{
if(a[k]>max)
{
result=k;
max=a[k];
count=1;
}
else if(max==a[k])
count++;
}
if(count==1)
{
printf("The jumping champion is %d\n", result);
}
else
{
printf("No jumping champion\n");
}
}
return 0;
}
