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: #Codeforces handle - "@titanalpha"
  #Email id - shubhamnokiafan@gmail.com
  
  from collections import Counter, deque
  import math
  from random import randint
  from bisect import bisect
  import sys
  import re
  import copy
  
  MOD = 1000000007
  MAX = sys.maxsize
  MIN = -sys.maxsize
  
  class get:
      def int():
          return list(map(int,input().split()))
      def str():
          return input().split()
      def float():
          return list(map(float,input().split()))
      def map():
          return map(int,input().split())
  
  def sqrt(x):
      return int(math.sqrt(x))+1
  
  def gcd(*args):
      result = args[0]
      for item in args:
          result = math.gcd(result,item)
      return result
  
  def LCM(a,b):
      return (a*b)//(math.gcd(a,b))
  
  def solve():
      n,k = get.map()
      bi = bin(k).replace("0b","")
      sum_ = 0
      for i in range(len(bi)-1,-1,-1):
          if bi[i] == "1":
              sum_ += pow(n,len(bi)-1-i,MOD)
              sum_ = sum_%MOD
      print(sum_)
  for _ in range(int(input())):
      solve()