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 java.io.*;
  import java.util.*;
  public class new1{
  	public static long power(long a, long b, long mod) {
  		if(b == 0) return 1;
  		if(b == 1)  return a;
  		long a1 = power(a, b / 2, mod);
  		long ans = (a1 * a1) % mod;
  		ans = (ans * power(a, b - 2*(b / 2), mod)) % mod;
  		return ans;	
  		
  	}
  	
  
      public static void main(String[] args)  throws IOException{
      	FastReader s = new FastReader();
      	BufferedWriter output = new BufferedWriter(new OutputStreamWriter(System.out));
      	int t = s.nextInt();	
      	for(int i = 0; i < t; i++) {
      		long n = s.nextInt();
      		long k = s.nextInt();
      		long mod = 1000000007;
      		String str = Long.toBinaryString(k);
      		//System.out.println(str);
      		long ans = 0;
      		for(int j = 0; j < str.length(); j++) {
      			int ind =  (str.length() - 1) - j;
      			if(str.charAt(ind) == '1') {
      				//System.out.println(j);
      				ans = (ans + power(n, j, mod)) % mod;
      			}
      			
      		}
      		System.out.println(ans);
      		
  
      		
      		
      			
      	}
      }
  }
  class FastReader {
      BufferedReader br;
      StringTokenizer st;
      public FastReader() {
          br = new BufferedReader(new InputStreamReader(System.in));
      }
      String next() {
          while (st == null || !st.hasMoreElements()) {
              try {
                  st = new StringTokenizer(br.readLine());
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
          return st.nextToken();
      }
   
      public int nextInt() {
          return Integer.parseInt(next());
      }
   
      long nextLong() {
          return Long.parseLong(next());
      }
   
      double nextDouble() {
          return Double.parseDouble(next());
      }
   
      String nextLine() {
          String str = "";
          try {
              str = br.readLine();
          } catch (IOException e) {
              e.printStackTrace();
          }
          return str;
  }}