#include <iostream>

using namespace std;

int main()
{
    int n, n1, n2, c, p1, p2;
    cin>>n;
    n1=0; p1=1;
    n2=0; p2=1;
    while(n!=0)
    {
        c=n%10;
        if(c%2==0)
        {
            n1=n1+c*p1;
            p1=p1*10;
        }
        else
        {
            n2=n2+c*p2;
            p2=p2*10;
        }
        n=n/10;
    }
    if(n1>n2) cout<<n1-n2;
    if(n2>n1) cout<<n2-n1;
    return 0;
}