#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

 int ap[10];

int main()
{
    char sir[50];


    cin >> sir;

    long long cate = 0;

    if(strlen(sir) == 1)
    {
        cout << 1;
        return 0;
    }

    for(int i = 0; i < strlen(sir); i++)
    {
        int k = sir[i] - '0';
        ap[k] += 1;
   //     cout  << k <<" ";
     }
     int shit = 0;


    for(int i = 0; i < 10; i++)
    {
        if(ap[i] % 2 == 1)
            {
                shit += 1;
                ap[i] -= 1;
            }
        if(shit >= 2)
        {
            cout << 0;
            return 0;
        }
    }
    string cacat;
    char aux[50];
    int k = 0;
    for(int i = 0; i < 10; i++)
    {
        if(ap[i] != 0  && ap[i] % 2 == 0)
        {
            ap[i] /= 2;
            char ll = (i + '0');
            while(ap[i])
            {
                cacat += ll;
                ap[i] --;
            }
        }
    }


 for(int i = 0; i <= cacat.length(); i++)
    aux[i] = cacat[i];


    aux[strlen(aux)] = '\0';
    do
    {
        if(aux[0]  != '0')
        cate += 1;


    } while(next_permutation(aux,aux+strlen(aux)));
    cout << cate;
        return 0;
}