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: #include <bits/stdc++.h>
  using namespace std;
  long long mod = 1000000007;
  bool isprime(int n) {
    for (int i = 2; i * i <= n; i++) {
      if (n % i == 0) {
        return false;
      }
    }
    return true;
  }
  vector<long long> block(int x) {
    vector<int> v;
    while (x > 0) {
      v.push_back(x % 2);
      x = x / 2;
    }
    vector<long long> ans;
    for (int i = 0; i < v.size(); i++) {
      if (v[i] == 1) {
        ans.push_back(i);
      }
    }
    return ans;
  }
  void solve() {
    int n, k;
    cin >> n >> k;
    vector<long long> v1 = block(k);
    unsigned long long ans = 0;
    for (long long i = 0; i < v1.size(); i++) {
      unsigned long long t1 = 1;
      for (int j = 1; j <= v1[i]; j++) {
        t1 = t1 * n;
        t1 = t1 % mod;
      }
      ans += t1;
      ans = ans % mod;
    }
    cout << ans % mod << endl;
    return;
  }
  int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int _t;
    _t = 1;
    cin >> _t;
    while (_t--) solve();
  }
  