BF解CF--Number Sequence



Number Sequence
Time Limit:1000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u
SubmitStatus






Description




Mr. Kitayuta has kindly given you a string s consisting of lowercase English letters. You are asked to insert exactly one lowercase English letter into s to make it a palindrome. A palindrome is a string that reads the same forward and backward. For example, "noon", "testset" and "a" are all palindromes, while "test" and "kitayuta" are not.


You can choose any lowercase English letter, and insert it to any position of s, possibly to the beginning or the end of s. You have to insert a letter even if the given string is already a palindrome.


If it is possible to insert one lowercase English letter into s so that the resulting string will be a palindrome, print the string after the insertion. Otherwise, print "NA" (without quotes, case-sensitive). In case there is more than one palindrome that can be obtained, you are allowed to print any of them.




Input




The only line of the input contains a string s (1 ≤ |s| ≤ 10). Each character in s is a lowercase English letter.




Output




If it is possible to turn s into a palindrome by inserting one lowercase English letter, print the resulting string in a single line. Otherwise, print "NA" (without quotes, case-sensitive). In case there is more than one solution, any of them will be accepted. 




Sample Input






 Input 
revive


 Output 
reviver


 Input 
ee


 Output 
eye


 Input 
kitayuta


 Output 
NA










Hint




For the first sample, insert 'r' to the end of "revive" to obtain a palindrome "reviver".


For the second sample, there is more than one solution. For example, "eve" will also be accepted.


For the third sample, it is not possible to turn "kitayuta" into a palindrome by just inserting one letter.

#include
#include
using namespace std;
char s[20],a[20];
int l;
int hw(char *a)
{
    int i,l=strlen(a),s=0;
    for(i=0;i
刚开始没什么思路的,然后百度一下(表示自己真的弱,只能百度),BF可解。题目的字符长度是10,也就解释了第三个数据只能NA。

BF怎么解呢- -26个字母,11个空,挨个插进去。判断回文AC!

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