description: Theofanis really likes sequences of positive integers, thus his teacher (Yeltsa Kcir) gave him a problem about a sequence that consists of only special numbers.
  
  Let's call a positive number special if it can be written as a sum of different non-negative powers of n. For example, for n = 4 number 17 is special, because it can be written as 4^0 + 4^2 = 1 + 16 = 17, but 9 is not.
  
  Theofanis asks you to help him find the k-th special number if they are sorted in increasing order. Since this number may be too large, output it modulo 10^9+7.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of test cases.
  
  The first and only line of each test case contains two integers n and k (2 ≤ n ≤ 10^9; 1 ≤ k ≤ 10^9).
  
  Output
  
  For each test case, print one integer — the k-th special number in increasing order modulo 10^9+7.
  
  Example
  
  Input
  
  
  3
  3 4
  2 12
  105 564
  
  
  Output
  
  
  9
  12
  3595374
  
  Note
  
  For n = 3 the sequence is [1,3,4,9...]
solution: import java.io.*;
  import java.util.Scanner;
  
  
  public class Main
  {
      public static void main(String[] args) throws IOException
      {
          StreamTokenizer sc =new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
      	PrintWriter out=new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
          // Scanner sc=new Scanner(System.in);
          sc.nextToken();
          int t=(int)sc.nval;
  
          while (t-->0) {
              sc.nextToken();
              int n=(int)sc.nval;
              sc.nextToken();
              int k=(int)sc.nval;
              if (n==2) {
                  out.println(k);
                  continue;
              }
              long ans=0;
              long now=1;
              while (k>0) {
                  if ((k&1)==1) {
                      ans+=now;
                      ans%=1000000007;
                  }
  
                  k>>=1;
                  now*=n;
                  now%=1000000007;
              }
              out.println(ans);
  
              
          }
          out.flush();
          
          
      }
  }