#include <iostream>

using namespace std;

int main(){
    int n, n1 = 0, n2 = 0, d, a, c1=1, c2=1;
    cin >> n;
    do{
        a = n%10;
        if(a%2==0){
            n2=n2+c2*a;
            c2*=10;
        }
        else{
            n1=n1+c1*a;
            c1*=10;
        }
        n/=10;
    }while(n!=0);
    if(n1 > n2){
       d = n1 - n2;
    }
    else{
        d = n2 - n1;
    }
    cout << d;
    return 0;
}