Codeforces Round #305 (Div. 2) A

Description

While Mike was walking in the subway, all the stuff in his back-bag dropped on the ground. There were several fax messages among them. He concatenated these strings in some order and now he has string s.



He is not sure if this is his own back-bag or someone else's. He remembered that there were exactly k messages in his own bag, each was a palindrome string and all those strings had the same length.

He asked you to help him and tell him if he has worn his own back-bag. Check if the given string s is a concatenation of k palindromes of the same length.

Input
The first line of input contains string s containing lowercase English letters (1 ≤ |s| ≤ 1000).

The second line contains integer k (1 ≤ k ≤ 1000).

Output
Print "YES"(without quotes) if he has worn his own back-bag or "NO"(without quotes) otherwise.

Examples

input

saba
2

output

NO

input

saddastavvat
2

output

YES

首先长度不能整除的当然不符合要求。
然后我们按照要求分割字符串，判断是不是回文串就好了

#include<iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
int main()
{
string s;
int n;
cin>>s;
cin>>n;
if(s.length()%n)
{
cout<<"NO"<<endl;
}
else
{
int i,j;
int mid=s.length()/n;
for(i=0;i<n;i++)
{
string ss=s.substr(i*mid,mid);
for(int j=0;j<=ss.length()/2;j++)
{
if(ss[j]!=ss[ss.length()-1-j])
{
cout<<"NO"<<endl;
return 0;
}
}
//   cout<<ss<<endl;
}
cout<<"YES"<<endl;

}

return 0;
}