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.IOException;
  import java.io.InputStreamReader;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Set;
  import java.util.StringTokenizer;
  import java.util.TreeSet;
  
  /*aman-shri*/
  
  public class B {
  
      public static void main(String[] args) {
          FastScanner fs=new FastScanner();
          int T=fs.nextInt();
          for (int tt=0; tt<T; tt++) {
          	int n = fs.nextInt(), k = fs.nextInt();
          	long a = 1;
          	long ans = 0;
          	while(k!=0) {
          		if(k%2==1) {
          			ans = (long) ((ans+a)%(1_000_000_000 + 7));
          		}
          		a = ((a*n)%(1_000_000_000 + 7));
          		k /= 2;
          	}
          	
          	
          	System.out.println(ans);
          }
         
      }
      
      static class Pair {
          int x;
          int y;
  
          public Pair(int x, int y) {
              this.x = x;
              this.y = y;
          }
          public int getX() {
              return this.x;
          }
          public int getY() {
              return this.y;
          }
      }
  
      static void sort(int[] a) {
          ArrayList<Integer> l=new ArrayList<>();
          for (int i:a) l.add(i);
          Collections.sort(l);
          for (int i=0; i<a.length; i++) a[i]=l.get(i);
      }
  
      static class FastScanner {
          BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
          StringTokenizer st=new StringTokenizer("");
          String next() {
              while (!st.hasMoreTokens())
                  try {
                      st=new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              return st.nextToken();
          }
  
          int nextInt() {
              return Integer.parseInt(next());
          }
          int[] readArray(int n) {
              int[] a=new int[n];
              for (int i=0; i<n; i++) a[i]=nextInt();
              return a;
          }
          long nextLong() {
              return Long.parseLong(next());
          }
      }
  
  
  }
  
  
  
  