#include <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
using ll = long long;
using namespace std;
int main() {
  	int aw, ab, bw, bb, c, d;
    cin >> aw >> ab >> bw >> bb >> c >> d;
    
    aw -= max(c-ab, 0);
    bw += max(c-ab, 0);
    aw += min(d, bw);
    
    cout << aw << endl;
  	return 0;
}