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: # -*- coding: utf-8 -*-
  """
  Created on Fri Oct 15 16:55:24 2021
  
  @author: ThanhNT
  """
  # bước 1 chuyển số k về nhị phân
  # bước 2 tính tổng theo công thức
  max_value = 10**9 + 7
  def special_number(n, k):    
      b = bin(k).replace("0b", "")        
      #print(b)
      
      i = len(b)
      result = 0
      for index in range (len(b)):
          i -=1
          result = result + int(b[index])*(n**i)
          index +=1
          if result > max_value:
              result = result % max_value
      return result
  
  
  if __name__ == "__main__":
  
      t = int(input())
      for _ in range(0, t):
          n, k = map(int,input().split(" "))
          print (special_number(n, k))