1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cmath>
 5 #include <algorithm>
 6 #include <climits>
 7 #include <vector>
 8 #include <queue>
 9 #include <cstdlib>
10 #include <string>
11 #include <set>
12 #include <stack>
13 #define LL long long
14 #define pii pair<int,int>
15 #define INF 0x3f3f3f3f
16 using namespace std;
17 LL lt,rt;
18 LL test(LL x){
19     int d[20],i = 0,j,sum = 0;
20     LL y = x;
21     while(x){d[i++] = x%10; x /= 10;}
22     for(j = 0; j < i; j++){
23         if(j&1)sum -= d[j];
24         else sum += d[j];
25     }
26     if(sum != 3) return y;
27     return -1;
28 }
29 int main() {
30     int t;
31     LL tst;
32     scanf("%d",&t);
33     while(t--){
34         scanf("%I64d %I64d",&lt,&rt);
35         bool flag = false;
36         for(LL i = lt/11+1; i*11+3 <= rt; i++){
37             tst = test(i*11+3);
38             if(tst > 0) {flag = true;break;}
39         }
40         if(flag) printf("%I64d\n",tst);
41         else puts("-1");
42     }
43     return 0;
44 }