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.BufferedReader;
  import java.io.StreamTokenizer;
  import java.io.PrintWriter;
  import java.io.InputStreamReader;
  import java.io.BufferedOutputStream;
  import java.io.IOException;
  import java.util.Scanner;
  
  public class Main {
      static BufferedReader BR = new BufferedReader(new InputStreamReader(System.in));
      static StreamTokenizer IN = new StreamTokenizer(BR);
      static PrintWriter OUT = new PrintWriter(new BufferedOutputStream(System.out));
      static int nextInt() throws IOException {
          IN.nextToken();
          return (int) IN.nval;
      }
      static double nextDouble() throws IOException {
          IN.nextToken();
          return IN.nval;
      }
      static String nextStr() throws IOException {
          IN.nextToken();
          return IN.sval;
      }
      static String nextLine() throws IOException {
          return BR.readLine();
      }
  
      static int MAXN = 100050;
      static long T, N, M, P;
  
  //    static int[] BIT = new int[MAXN+10];
  //    static int sum(int i) {
  //        int tot = 0;
  //        while(i > 0) {
  //            tot += BIT[i];
  //            i -= i&-i;
  //        }
  //        return tot;
  //    }
  //    static void add(int i, int x) {
  //        while(i <= N) {
  //            BIT[i] += x;
  //            i += i&-i;
  //        }
  //    }
  
      public static void main(String[] args) throws IOException {
          Scanner sc = new Scanner(System.in);
          T = sc.nextInt();
          long mod = (long) (1e9+7);
          while(T-- > 0) {
              N = sc.nextLong();
              M = sc.nextLong();
              if(M == 1) {
                  OUT.println(1);
                  continue;
              }
  
              long ans = 0;
              long j = 1;
              while(M > 0) {
                  if((M&1) == 1) {
                      ans = (ans+j)%mod;
                  }
                  M/=2;
                  j=(j*N)%mod;
              }
              OUT.println(ans);
          }
  
          OUT.flush();
      }
  }