# codeforces-1073A Diverse Substring

You are given a string ss, consisting of n lowercase Latin letters.A substring of string ss is a continuous segment of letters from s. For example, "defor" is a substring of "codeforces" and "fors" is not.

The length of the substring is the number of letters in it.

Let's call some string of length nn diverse if and only if there is no letter to appear strictly more than n/2 times. For example, strings "abc" and "iltlml" are diverse and strings "aab" and "zz" are not.

Your task is to find any diverse substring of string s or report that there is none. Note that it is not required to maximize or minimize the length of the resulting substring.

Input

The first line contains a single integer nn (1n1000) — the length of string s.

The second line is the string s, consisting of exactly nn lowercase Latin letters.

Output

Print "NO" if there is no diverse substring in the string ss.

Otherwise the first line should contain "YES". The second line should contain anydiverse substring of string ss.

Examples

Input
10
codeforces
Output
YES
code
Input
5
aaaaa
Output
NO

Note

The first example has lots of correct answers.

#include<bits/stdc++.h>
using namespace std;
int main()
{
string s;
int n;
cin>>n;
cin>>s;
for(int i=0;i<n-1;i++)
{
if(s[i]!=s[i+1])
{
cout<<"YES"<<endl;
cout<<s[i]<<s[i+1]<<endl;
return 0;

}
}
cout<<"NO"<<endl;
}