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 io, os
  import sys 
  from sys import stdin
  
  from bisect import bisect_left, bisect_right
  from collections import defaultdict, deque, namedtuple
  from math import gcd, ceil, floor
  from itertools import combinations, permutations
  
  input = sys.stdin.buffer.readline
  #input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline
  # input = sys.stdin.readline
  
  def work(n, k):
      mod = 10 ** 9 + 7
      s = bin(k)
      s = s[2:]
      # print(s)
      m = len(s)
      ans = 0 
      for i in range(m):
          if s[i] == "1":
              ans = (ans + pow(n, m - i - 1, mod)) % mod 
      print(ans)
  
      return 
  
  
  def main():
      test = int(input())
  
      for idt in range(test):
          n, k = map(int, input().split())
          work(n, k)
      
      return 
  
  
  if __name__ == '__main__':
      main()