#include <bits/stdc++.h>
using namespace std;
int main() {
    vector <int> a;
    int temp;
    while (cin >> temp) {
        a.push_back(temp);
        if (cin.get() == '\n') {
            break;
        }
    }
    for (int i = 0; i < a.size(); i++) {
        if (a[i] % 4 == 0) {
            cout << i + 1;
        }
    }
    return 0;
}