#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <map>

using namespace std;


int main()
{
    int x, y;
    cin >> x >> y;

    int x1 = min(x, y);
    int y1 = max(x, y);

    cin >> x >> y;

    int x2 = min(x, y);
    int y2 = max(x, y);

    if (x2 > x1 || y2 > y1)
    {
        cout << -1;
        return 0;
    }

    int ans = 0;
    while (x1 != x2)
    {
        if (x1 - x2 > x2)
        {
            x1 = (x1 % 2) + (x1 / 2);
        }
        else
            x1 = x2;
        ans++;
        if (x1 > y1)
            swap(x1, y1);
    }

    while (y1 != y2)
    {
        if (y1 - y2 > y2)
        {
            y1 = (y1 % 2) + (y1 / 2);
        }
        else
            y1 = y2;
        ans++;
        if (x1 > y1)
            swap(x1, y1);
    }

    cout << ans;

    return 0;
}