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: /* package codechef; // don't place package name! */
  
  import java.util.*;
  import java.lang.*;
  import java.io.*;
  
  /* Name of the class has to be "Main" only if the class is public. */
  public class Codechef
  {   static long mod=1000000007;
  	public static void main (String[] args) throws java.lang.Exception
  	{
  		//your code goes here
  Scanner sc=new Scanner(System.in);
  int t=sc.nextInt();
  while(t>0){t--;
  		    long n=sc.nextLong();
  		    long k=sc.nextLong();
  		    long ans=0;
  		 
  		    for(int i=0;i<=36;i++){
  		        if((k&1)==1){
  		            ans=(ans%mod+pow(n,i))%mod;
  		        }
  		        k=k>>1;
  		    }
  		    
  		    System.out.println(ans%mod);
  	}}
  	
  	static long pow(long a,long b){
  	    long ans=1;
  	    for(int i=0;i<b;i++){
  	        ans=(ans*a)%mod;
  	        
  	    }
  	    return ans%mod;
  	    
  	}
  }