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: from math import ceil, log, floor
  from collections import defaultdict,deque
  import sys
  import os.path
  
  sys.setrecursionlimit(200000)
  if (os.path.exists('input.txt')):
      sys.stdin = open("input.txt", "r+")
      sys.stdout = open("output.txt", "w")
  
  
  # input = sys.stdin.readline
  # print=sys.stdout.write
  def MI():
      return map(int, input().split())
  
  mod=10**9+7
  
  def solve():
      # n = int(input())
      n,k=MI()
      # a=list(MI())
      # print(1,((1+8*n)**(1/2)-1)//2)
      # 
      ans=0
      while(k>0):
          r=0
          for i in range(0,34):
              if 2**i>k:
                  break
              r=i
          ans+=(n**r)%mod
          k-=2**r
          # print(ans)
      print(ans%mod)
  
  
  
  
      
      
      
  
  
  
  
  
     
                  
  
  
  
  
  
      
  
  
  
          
  
      
  
      
  
  
  
  t=int(input())
  for _ in range(t):
      solve()