#include<bits/stdc++.h>
using namespace std;
int main()
{
    int a, b, x, y, c, z, d;
    cin >> a >> b >> x >> y;
    c = min(a, x);
    z = min(b, y);
    d = (a + b + x + y) * 2 - min(c, z) * 2;
    cout << d;
}

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