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 com.company;
  
  import java.util.*;
  import java.lang.*;
  import java.io.*;
  
  public class Rough_Work {
      public static void main(String[] args) throws IOException {
          FastReader sc = new FastReader();
          PrintWriter out = new PrintWriter(System.out);
  
          int t = sc.nextInt();
          while (t-->0) {
              long n = sc.nextLong();
              int k = sc.nextInt();
  
              String s = Integer.toBinaryString(k);
  
              long sum = 0, mod = 1000000007, power = 1L;
              for (int i = s.length()-1; i >= 0; i--) {
                  if (s.charAt(i) == '1') sum = (sum%mod + power%mod)%mod;
                  power = ((power%mod) * (n%mod))%mod;
              }
  
              out.println(sum);
          }
  
          sc.close();
          out.close();
      }
      static class FastReader {
          final private int BUFFER_SIZE = 1 << 17;
          private DataInputStream din;
          private byte[] buffer;
          private int bufferPointer, bytesRead;
  
          public FastReader()
          {
              din = new DataInputStream(System.in);
              buffer = new byte[BUFFER_SIZE];
              bufferPointer = bytesRead = 0;
          }
  
          public FastReader(String file_name) throws IOException
          {
              din = new DataInputStream(
                      new FileInputStream(file_name));
              buffer = new byte[BUFFER_SIZE];
              bufferPointer = bytesRead = 0;
          }
  
          public String readLine() throws IOException
          {
              byte[] buf = new byte[128]; // line length
              int cnt = 0, c;
              while ((c = read()) != -1) {
                  if (c == '\n') {
                      if (cnt != 0) {
                          break;
                      }
                      else {
                          continue;
                      }
                  }
                  buf[cnt++] = (byte)c;
              }
              return new String(buf, 0, cnt);
          }
  
          public int nextInt() throws IOException
          {
              int ret = 0;
              byte c = read();
              while (c <= ' ') {
                  c = read();
              }
              boolean neg = (c == '-');
              if (neg)
                  c = read();
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
  
              if (neg)
                  return -ret;
              return ret;
          }
  
          public long nextLong() throws IOException
          {
              long ret = 0;
              byte c = read();
              while (c <= ' ')
                  c = read();
              boolean neg = (c == '-');
              if (neg)
                  c = read();
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
              if (neg)
                  return -ret;
              return ret;
          }
  
          public double nextDouble() throws IOException
          {
              double ret = 0, div = 1;
              byte c = read();
              while (c <= ' ')
                  c = read();
              boolean neg = (c == '-');
              if (neg)
                  c = read();
  
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
  
              if (c == '.') {
                  while ((c = read()) >= '0' && c <= '9') {
                      ret += (c - '0') / (div *= 10);
                  }
              }
  
              if (neg)
                  return -ret;
              return ret;
          }
  
          public int[] nextIntArray(int size) throws IOException {
              int[] arr = new int[size];
              for (int i = 0; i < size; i++) {
                  arr[i] = nextInt();
              }
              return arr;
          }
  
          public long[] nextLongArray(int size) throws IOException {
              long[] arr = new long[size];
              for (int i = 0; i < size; i++) {
                  arr[i] = nextLong();
              }
              return arr;
          }
  
          public Double[] nextDoubleArray(int size) throws IOException {
              Double[] arr = new Double[size];
              for (int i = 0; i < size; i++) {
                  arr[i] = nextDouble();
              }
              return arr;
          }
  
          public int[][] nextIntMatrix(int n, int m) throws IOException {
              int[][] arr = new int[n][m];
              for (int i = 0; i < n; i++) {
                  arr[i] = nextIntArray(m);
              }
              return arr;
          }
  
          public long[][] nextLongMatrix(int n, int m) throws IOException {
              long[][] arr = new long[n][m];
              for (int i = 0; i < n; i++) {
                  arr[i] = nextLongArray(m);
              }
              return arr;
          }
  
          public ArrayList<Integer> nextIntList(int size) throws IOException {
              ArrayList<Integer> arrayList = new ArrayList<>(size);
              for (int i = 0; i < size; i++) {
                  arrayList.add(nextInt());
              }
              return arrayList;
          }
  
          public ArrayList<Long> nextLongList(int size) throws IOException {
              ArrayList<Long> arrayList = new ArrayList<>(size);
              for (int i = 0; i < size; i++) {
                  arrayList.add(nextLong());
              }
              return arrayList;
          }
  
          private void fillBuffer() throws IOException
          {
              bytesRead = din.read(buffer, bufferPointer = 0,
                      BUFFER_SIZE);
              if (bytesRead == -1)
                  buffer[0] = -1;
          }
  
          private byte read() throws IOException
          {
              if (bufferPointer == bytesRead)
                  fillBuffer();
              return buffer[bufferPointer++];
          }
  
          public void close() throws IOException
          {
              if (din == null)
                  return;
              din.close();
          }
      }
  }
  