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.util.*;
  // import java.lang.*;
  import java.io.*;
  
  //           THIS TEMPLATE MADE BY AKSH BANSAL.
  
  public class Solution {
      static 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();
          }
  
          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;
          }
      }
      private static boolean[] isPrime;
      private static void primes(){
          int num = (int)1e6; // PRIMES FROM 1 TO NUM
          isPrime = new boolean[num];
       
          for (int i = 2; i< isPrime.length; i++) {
             isPrime[i] = true;
          }
          for (int i = 2; i< Math.sqrt(num); i++) {
             if(isPrime[i] == true) {
                for(int j = (i*i); j<num; j = j+i) {
                   isPrime[j] = false;
                }
             }
          }
      }
      static void sort(int a[]){ // int -> long
          ArrayList<Integer> arr=new ArrayList<>(); // Integer -> Long
          for(int i=0;i<a.length;i++)
          arr.add(a[i]);
          Collections.sort(arr);
          for(int i=0;i<a.length;i++)
          a[i]=arr.get(i);
          
      }
      private static long gcd(long a, long b){
          if(b==0)return a;
          return gcd(b,a%b);
      }
      private static long pow(long x,long y){
          if(y==0)return 1;
          long temp = pow(x, y/2)%mod;
          if(y%2==1){
              return (((x*temp)%mod)*temp)%mod;
          }
          else{
              return (temp*temp)%mod;
          }
      }
  
      static PrintWriter out;
      static FastReader sc ;
      public static void main(String[] args) throws IOException {
          sc = new FastReader();
          out = new PrintWriter(System.out);
          // primes();
          // ________________________________
  
          int test = sc.nextInt();
          StringBuilder output = new StringBuilder();
  
          while (test-- > 0) {
              int n = sc.nextInt();
              int k = sc.nextInt();
  
              output.append(solver(n, k)).append("\n");
          }
  
          out.println(output);
          // _______________________________
  
          // int n = sc.nextInt();
          // out.println(solver());
          // ________________________________
          out.flush();
      }
      static int mod = (int)1e9+7;
  
      public static long solver(int n, int k) {
          long res=  0;
          int count =0;
          while(k>0){
              if(k%2==1){
                  res=(res+pow(n,count))%mod;
              }
              k/=2;
              count++;
              res%=mod;
          }
          return res%mod;
      }
  }