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: '''  Interesting Pairs
  
  https://codeforces.com/contest/1592/problem/A
  '''
  
  import io, os, sys
  input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline  # decode().strip() if str
  output = sys.stdout.write
  
  MOD = 10**9 + 7
  
  def solve(N, K):
  	res = 0
  	p = 1
  	while K > 0:
  		if K & 1: res = (res + p) % MOD
  		p = (p*N) % MOD
  		K >>= 1
  	return res
  
  def main():
  	T = int(input())
  	for _ in range(T):
  		N, K = list(map(int, input().split()))
  		out = solve(N, K)
  		output(str(out) + '\n')
  
  if __name__ == '__main__':
  	main()
  
  '''
  
  
  '''