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 MyPackage;
  import java.io.*;
  import java.util.*;
  
  public class MyClass {
      final static long mod = 1_000_000_007;
      final static int mini = Integer.MIN_VALUE;
      final static int maxi = Integer.MAX_VALUE;
      static long gcd(long a, long b) {
          if (b == 0) return a;
          return gcd(b, a % b);
      }
      static long ncr(long n, long r) {
          if (r > n - r) r = n - r;
          long[] C = new long[(int) r + 1];
          C[0] = 1;
          for (int i = 1; i <= n; i++) {
              for (long j = Math.min(i, r); j > 0; j--)
                  C[(int) j] = (C[(int) j] + C[(int) j - 1]) % mod;
          }
          return C[(int) r];
      }
      static boolean isPrime(long n) {
          if (n <= 1)
              return false;
          else if (n == 2)
              return true;
          else if (n % 2 == 0)
              return false;
          for (int i = 3; i <= Math.sqrt(n); i += 2) {
              if (n % i == 0)
                  return false;
          }
          return true;
      }
      static boolean isPalindrome(String s) {
          int i = 0, j = s.length() - 1;
          while(i < j) {
              if(s.charAt(i) != s.charAt(j)) return false;
              i++;
              j--;
          }
          return true;
      }
      static long lcm(long a, long b) {
          return (a / gcd(a, b)) * b;
      }
      static void sort(long[] a) {
          ArrayList<Long> l = new ArrayList<>();
          for (long value : a) {
              l.add(value);
          }
          Collections.sort(l);
          for (int i = 0; i < l.size(); i++)
              a[i] = l.get(i);
      }
      static int ceil(int a, int b) {
          return a % b == 0 ? a / b : a / b + 1;
      }
      static void sort(int[] a) {
          ArrayList<Integer> l = new ArrayList<>();
          for (int value : a) {
              l.add(value);
          }
          Collections.sort(l);
          for (int i = 0; i < l.size(); i++)
              a[i] = l.get(i);
      }
      static void reverse(int[] arr) {
          int l = 0;
          int h = arr.length - 1;
          while (l < h) {
              swap(arr, l, h);
              l++;
              h--;
          }
      }
      static String reverse(String s) {
          StringBuilder res = new StringBuilder(s);
          return res.reverse().toString();
      }
      static void swap(int[] arr, int i, int j) {
          int temp = arr[i];
          arr[i] = arr[j];
          arr[j] = temp;
      }
      static class FastReader {
          BufferedReader br;
          StringTokenizer st;
  
          public FastReader() {
              br = new BufferedReader(new InputStreamReader(System.in));
          }
  
          String n() {
              while (st == null || !st.hasMoreElements()) {
                  try {
                      st = new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              }
              return st.nextToken();
          }
  
          int nint() {
              return Integer.parseInt(n());
          }
  
          long nlong() {
              return Long.parseLong(n());
          }
  
          double ndouble() {
              return Double.parseDouble(n());
          }
  
          int[] narr(int n) {
              int[] a = new int[n];
              for (int i = 0; i < n; i++) a[i] = nint();
              return a;
          }
          int[][] narr(int n, int m) {
              int[][] a = new int[n][m];
              for (int i = 0; i < n; i++)
                  for (int j = 0; j < m; j++)
                      a[i][j] = nint();
              return a;
          }
  
          String nline() {
              String str = "";
              try {
                  str = br.readLine();
              } catch (IOException e) {
                  e.printStackTrace();
              }
              return str;
          }
      }
      static class Pair implements Comparable<Pair> {
          int a, b;
          Pair(int a, int b) {
              this.a = a;
              this.b = b;
          }
          public int compareTo(Pair p) {
              return -Integer.compare(a, p.a);
          }
      }
      public static void main(String[] args) {
          FastReader sc = new FastReader();
          PrintWriter out = new PrintWriter(System.out);
          // int t = 1;
          int t = sc.nint();
          while(t-- > 0) {
              long x = sc.nlong();
              long k = sc.nlong();
              String s = Long.toBinaryString(k);
              int n = s.length();
              //out.println(s);
              long sum = 0;
              for(int i = n - 1; i >= 0; i--) {
                  if(s.charAt(i) == '1') {
                      sum = (sum + power(x, n - 1 - i)) % mod;
                  }
              }
              out.println(sum);
          }
          out.flush();
          out.close();
      }
      static long power(long x, long i) {
          long res = 1;
          while(i-- > 0) {
              res = (res * x) % mod;
          }
          return res;
      }
  }