#include<iostream>
#include<vector>
#include<cmath>
using namespace std;
long long n, c, p;
int main(){
    cin >> n;
    vector <long long> a(n + 1); c = 0; p = 1; bool zero = false;
    for (long long i = 1; i < n + 1; ++i){
        cin >> a[i];
        c += abs(abs(a[i]) - 1);
        if (a[i] < 0) p *= -1;
        if (a[i] == 0) zero = true;
    }
    if (p == 1) cout << c;
    else if (zero) cout << c;
    else cout << c + 2;

}