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: // Problem: B. Special Numbers
  // Contest: Codeforces - Codeforces Round #747 (Div. 2)
  // URL: http://codeforces.com/contest/1594/problem/B
  // Memory Limit: 256 MB
  // Time Limit: 2000 ms
  // 
  // Powered by CP Editor (https://cpeditor.org)
  
  import java.io.*;
  import java.util.*;
  
  import static java.lang.Math.max;
  import static java.lang.Math.min;
  import static java.lang.Math.abs;
  
  
  /**
   * zxz 
   * problem link:
   **/
  public class Main {
      //put some data here
  
      /**
       * do some clean action before next testcase
       */
      private void clear() {
  
      }
  
  
      private void solve() throws Exception {
          rf();
          int n = readInt();
          int k = readInt();
          long ans = 0;
          long mod = 1000000007;
          long t = 1;
          for(int i = 0; i < 31; i++){
          	if(((1 << i) & k) > 0){
          		ans += t;
          		ans %= mod;
          	}
          	t *= n;
          	t %= mod;
          }
          addAns(ans);
          //int m = readInt();
          
          //sb.append( + "\n");
  
      }
  
      private void run() throws Exception {
  
         rf();
         int T = readInt();
          // int T = 1;
  
          while (T-- > 0) {
              solve();
              if (T != 0) {
                  clear();
              }
          }
          printAns();
      }
  
      public static void main(String[] args) throws Exception {
          new Main().run();
      }
  
      StringBuilder sb = new StringBuilder();
      BufferedReader infile = new BufferedReader(new InputStreamReader(System.in));
      StringTokenizer st;
  
      private void rf() throws IOException {
          st = new StringTokenizer(infile.readLine());
      }
  
      private int readInt() {
          return Integer.parseInt(st.nextToken());
      }
  
      private long readLong() {
          return Long.parseLong(st.nextToken());
      }
  
  	private void addAns(int a){
  		sb.append(a + "\n");
  	}
  	
  	private void addAns(long a){
  		sb.append(a + "\n");
  	}
  	
  	private void addAns(String s){
  		sb.append(s + "\n");
  	}
  
      private void printAns() {
          System.out.println(sb);
      }
  
      private int[] readArr(int N) throws Exception {
          int[] arr = new int[N];
          rf();
          for (int i = 0; i < N; i++) {
              arr[i] = Integer.parseInt(st.nextToken());
          }
          return arr;
      }
  
      private void print(int[] arr) {
          //for debugging only
          for (int x : arr) {
              System.out.print(x + " ");
          }
          System.out.println();
      }
  
      private long[] readArr2(int N) throws Exception {
          long[] arr = new long[N];
          st = new StringTokenizer(infile.readLine());
          for (int i = 0; i < N; i++) {
              arr[i] = Long.parseLong(st.nextToken());
          }
          return arr;
      }
  
      private boolean isPrime(long n) {
          if (n < 2) {
              return false;
          }
          if (n == 2 || n == 3) {
              return true;
          }
          if (n % 2 == 0 || n % 3 == 0) {
              return false;
          }
          long sqrtN = (long) Math.sqrt(n) + 1;
          for (long i = 6L; i <= sqrtN; i += 6) {
              if (n % (i - 1) == 0 || n % (i + 1) == 0) {
                  return false;
              }
          }
          return true;
      }
  
      private long gcd(long a, long b) {
          if (a > b) {
              a = (a + b) - (b = a);
          }
          if (a == 0L) {
              return b;
          }
          return gcd(b % a, a);
      }
  
  }
  