A Simple Sequence of Digits

During the break before math class, Roma decided to practice deciding whether a number is prime. Recall that a prime is a natural number with exactly two distinct natural divisors: one and itself. First he wrote the first prime on the board, then appended the second prime to its right, then the third, and so on. In total Roma wrote the first $n$ primes on the board. His work left a single long number on the board, which begins as <<23571113171923\dots>>.

When Yelena Yevgenyevna, Roma's teacher, entered the classroom, she gave the class the following task: cross out $k$ digits from the number on the board so that the remaining number is as large as possible.

Help Roma and his classmates solve the task, so that the strict teacher does not give them a failing grade.

The input file for this problem contains several test cases. The first line of the input file contains the number $T$, the number of test cases in the file.

The next $T$ lines describe the test cases, each consisting of two positive integers $n$ and $k$. It is guaranteed that the first $n$ primes contain at least $k + 1$ digits in total.

The sum of all $n$ in the input file does not exceed 400000.

For each test case, output the required maximum number for the corresponding $n$ and $k$ on a separate line.

In the first test, Roma wrote the number 2357. The largest number that can be obtained by crossing out two digits from it is 57.

In the second test, Roma wrote the number 235711. The largest number that can be obtained by crossing out three digits from it is 711.