B. Special Numberstime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputTheofanis 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.InputThe first line contains a single integer t (1 \le t \le 10^4) — the number of test cases.The first and only line of each test case contains two integers n and k (2 \le n \le 10^9; 1 \le k \le 10^9).OutputFor each test case, print one integer — the k-th special number in increasing order modulo 10^9+7.ExampleInput
3
3 4
2 12
105 564
Output
9
12
3595374
NoteFor n = 3 the sequence is [1,3,4,9...]
3
3 4
2 12
105 564

9 12 3595374 
['bitmasks', 'math', '*1100']