#include <vector> 
#include <list> 
#include <map> 
#include <set> 
#include <deque> 
#include <queue> 
#include <stack> 
#include <bitset> 
#include <algorithm> 
#include <functional> 
#include <numeric> 
#include <utility> 
#include <sstream> 
#include <iostream> 
#include <iomanip> 
#include <cstdio> 
#include <cmath> 
#include <cstdlib> 
#include <cctype> 
#include <string> 
#include <cstring> 
#include <ctime> 

using namespace std;

#define _int64 long long

_int64 solve(_int64 l,_int64 r)
{
  _int64 i;
  _int64 tmp,sum1,sum2,cnt;
  for (i=l;i<=r;i++)
    if (i%11==3)
    {
      tmp=i;
      cnt=0;
      sum1=0;sum2=0;
      while (tmp>0)
      {
        cnt++;
        if (cnt%2==0) sum1+=tmp%10;
        else sum2+=tmp%10;
        tmp/=10;
      }
      if (sum2-sum1!=3) return i;
    }
  return -1;
}

int main()
{
  int ll,t;
  _int64 l,r,ans;
  cin>>t;
  for (ll=0;ll<t;ll++)
  {
    cin>>l>>r;
    ans=solve(l,r);
    cout<<ans<<endl;
  }
}