CF1594B.Special Numbers

传统题 时间 2000 ms 内存 256 MiB 5 尝试 1 已通过 1 标签

Special Numbers

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 nn. For example, for n=4n = 4 number 1717 is special, because it can be written as 40+42=1+16=174^0 + 4^2 = 1 + 16 = 17, but 99 is not.

Theofanis asks you to help him find the kk-th special number if they are sorted in increasing order. Since this number may be too large, output it modulo 109+710^9+7.

Input

The first line contains a single integer tt (1t1041 \le t \le 10^4) — the number of test cases.

The first and only line of each test case contains two integers nn and kk (2n1092 \le n \le 10^9; 1k1091 \le k \le 10^9).

Output

For each test case, print one integer — the kk-th special number in increasing order modulo 109+710^9+7.

Note

For n=3n = 3 the sequence is [1,3,4,9...][1,3,4,9...]

Samples

3
3 4
2 12
105 564
9
12
3595374

在线编程 IDE

建议全屏模式获得最佳体验