#include <iostream>
using namespace std;


int main()
{
    int n, inv, n1=0, n2=0, cif,ct1=1,ct2=1;
    cin >> n;
    while(n != 0)
    {
       cif=n%10;
       if(cif%2==0)
       {
           n1=n1+cif*ct1;
           ct1*=10;;
       }
       else
       {
           n2=n2+cif*ct2;
           ct2*=10;
       }
       n/=10;
    }
    if(n1 >= n2) cout << n1 - n2;
            else cout << n2 - n1;
    return 0;
}