#include<iostream>
#include<cmath>
using namespace std;
int main ()
{
    int x,r1,cifra,r2,p1,p2,diferenta;;
    cin>>x;
    r1=0;
    p1=1;
    r2=0;
    p2=1;
    do
    {
        cifra=x%10;
        {
            if(cifra%2==0)
            {
                r1=r1+cifra*p1;
                p1=p1*10;
            }
            else
            {
                r2=r2+cifra*p2;
                p2=p2*10;
            }
            x=x/10;
        }
    }
        while(x>0);
        diferenta=abs(r1-r2);
        cout<<diferenta;
        return 0;
}