#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define int long long
#define ull unsigned long long
int T,n,m;
const int N = 1010,INF = 1e9;
string s;
int cnt[N];

void solve() 
{
	cin >> s;
	n = s.size();
	for(int i = 0;i < n;i++)
	{
	    cnt[s[i] - 'a']++;
	}
	int flag = -1;
	for(int i = 0;i < 26;i++)
	{
	    if(cnt[i] > n / 2) 
	    {
	        flag = i;
	        break;
	    }
	}
	if(flag == -1)
	{
	    cout << "YES" << endl;
	    sort(s.begin(),s.end());
	    cout << s << endl;
	    return ;
	}
	bool tmp = true;
	for(int i = 0;i < 26;i++)
	{
	    if(i == flag) continue;
	    if(cnt[i] >= 2) 
	    {
	        tmp = false;
	        break;
	    }
	}
	if(tmp)
	{
	    cout << "NO" << endl;
	    return ;
	}
	sort(s.begin(),s.end());
	cout << "YES" << endl;
	s.insert(s.begin() + n / 2,s[n - 1]);
	s.erase(prev(s.end()));
	cout << s << endl;
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    T = 1;
    while(T--)
    {
        solve();
    }
}