#include <iostream>
#include <vector>
#include <algorithm>
#include <string>

#define REP(i, a, b) for (int i = int(a); i < int(b); i++)
#define dump(val) cerr << __LINE__ << ":\t" << #val << " = " << (val) << endl

using namespace std;

typedef long long int lli;

const int mod = 1000000007;

int main() {
    int Aw, Ab, Bw, Bb, C, D;
    cin >> Aw >> Ab >> Bw >> Bb >> C >> D;
    int tmp = max(C - Ab, 0);
    Aw -= tmp; 
    Bw += tmp;
    cout << Aw + min(Bw, D) << endl;
    return 0;
}