A prime number (or a prime) is a natural number greater than 11 that cannot be formed by multiplying two smaller natural numbers.
Now lets define a number NN as the supreme number if and only if each number made up of an non-empty subsequence of all the numeric digits of NN must be either a prime number or 11.
For example, 1717 is a supreme number because 11, 77, 1717 are all prime numbers or 11, and 1919 is not, because 99 is not a prime number.
Now you are given an integer N\ (2 \leq N \leq 10^{100})N (2≤N≤10100), could you find the maximal supreme number that does not exceed NN?
Input
In the first line, there is an integer T\ (T \leq 100000)T (T≤100000) indicating the numbers of test cases.
In the following TT lines, there is an integer N\ (2 \leq N \leq 10^{100})N (2≤N≤10100).
Output
For each test case print "Case #x: y", in which xx is the order number of the test case and yy is the answer.
样例输入复制
2 6 100
样例输出复制
Case #1: 5 Case #2: 73
题目来源
一个数包含他的子串都不会是素数
[1,2,3,5,7,11,13,17,23,31,37,53,71,73,113,131,137, 173,311,313,317,373,1373,3137] |
一个数包含他的子序列都不会是素数
1,2,3,5,7,11,13,17,23,31,37,53,71,73,113,131,137,173,311,317,
原文地址：https://www.cnblogs.com/tingtin/p/9610150.html