#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef double db;

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	string s;
	cin >> s;
	int n = SZ(s) / 2;
	map<char, int> m;
	for (auto c : s)
		m[c]++;
	vector<pair<int, char>> v;
	for (auto [c, cnt] : m)
		v.PB({cnt, c});
	sort(ALL(v));
	if (SZ(v) >= 3)
	{
		cout << "YES\n";
		string t = "";
		FOR (i, 2, SZ(v))
			FOR (j, 0, v[i].F)
				t += v[i].S;
		FOR (i, 0, v[0].F)
			cout << v[0].S;
		FOR (i, 0, n - v[0].F)
			cout << t[i];
		FOR (i, 0, v[1].F)
			cout << v[1].S;
		FOR (i, 0, n - v[1].F)
			cout << t[i + v[0].F];
		cout << '\n';
	}
	else if (SZ(v) == 1)
	{
		cout << "NO\n";
	}
	else
	{
		if (v[0].F <= 2 && n > 2)
			cout << "NO\n";
		else if (n <= 2)
		{
			sort(ALL(s));
			cout << "YES\n";
			cout << s << '\n';
		}
		else
		{
			cout << "YES\n";
			cout << v[0].S;
			FOR (i, 0, n - 1)
				cout << v[1].S;
			FOR (i, 0, v[0].F - 1)
				cout << v[0].S;
			FOR (i, 0, v[1].F - n + 1)
				cout << v[1].S;
			cout << '\n';
		}
	}
	
	return 0;
}