题目描述

Lidia likes sets of prime numbers. When she is bored, she starts writing them down into the Extremely Long Notebook for Prime Sets.

Elements of each set are written down in ascending order. Each set of prime numbers appears in her notebook eventually. A set with a smaller sum always appears before a set with a larger sum. Sets with the same sum are sorted in ascending lexicographical order: they are compared by the first element, if the first elements are equal, then by second element, and so on.

Just in case someone decides to parse her notebook, she writes down her sets in a machine-readable JSON format. Of course, she puts a space after each comma. Here's the beginning of her notebook:

$[2], [3], [2 , 3], [5], [2 , 5], [7], [3 , 5], [2 , 7], [2 , 3 , 5], [3 , 7], [11], [2 , 3 , 7], [5 , 7], [2 , 11], [13], [2 , 5 , 7],$

Lidia wants to double-check her work, so here is her request for you: given two integers, $a$ and $b$ , output a substring of her notebook from the position $a$ to the position $b$ (inclusive, counting from $1$) .

输入格式

The first line contains two integers, $a$ and $b$ ($1 \le a \le b \le 10^{18}; b - a \le 10^{5}$).

输出格式

Output the substring of the notebook described in the problem statement from the position $a$ to the position $b$ . You must write a line with exactly $b - a + 1$ characters, including any leading or trailing spaces.

1 35

[2], [3], [2, 3], [5], [2, 5], [7],

36 41

 [3, 5

提示

Time limit: 2 s, Memory limit: 512 MB.