//created for znanija.com by duplerlvl85

#include <iostream>
#include <conio.h>
#include <string>

using namespace std;

bool isOk(int a[],int n);
bool checkArr(int a[], int n,int b);
bool printArr(int a[], int n , int b);
int pravda=0;

void main() {
	setlocale(0, "");
	int n = 0,mass=0;
	string str;
	cout << "Введите строку" << endl;
	getline(cin ,str);
	for (int i = 0;i < str.length();++i)
	{
		if ((int(str[i]) >= 48) && (int(str[i]) <= 57))
			n++;
	}
	int* arr = new int[n];
	for (int i = 0;i < str.length();++i)
	{
		if ((int(str[i]) >= 48) && (int(str[i]) <= 57))
		{
			arr[mass] = str[i] - '0';
			mass++;
		}
	}
	cout << endl;
	isOk(arr, n);
	if (pravda==0)
		cout << "NO" << endl;
	_getch();
}
bool isOk(int a[],int n) 
{
	for (int i = 0;i < n;++i)
	{
		for (int j =i+1;j < n;++j) 
		{
			if (a[i] == a[j]) 
			    {
					checkArr(a, j,i);
				}
			}
		}
	return false;
}
bool checkArr(int a[], int n,int b)
{
	int kk = 0, l = 0;
	int ind = n - b; 
	for (int i = b;i <= n;++i)
	{
		if (a[i] == a[n - l])
		{
			kk++;
			l++;
		}

	}
	if (ind+1 == kk)
	{
		pravda++;
		printArr(a, n , b);
		return true;
	}
}
bool printArr(int a[], int n , int b) {
	if (pravda == 1)
	{
		cout << "YES" << endl;
	}
	for (int i = b;i <= n;++i) 
	{
		cout << a[i];
	}
	cout << endl;
	return 1;
}