/* -*- coding: utf-8 -*-
 *
 * 149.cc: No.149 碁石の移動 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  int aw, ab, bw, bb, c, d;
  cin >> aw >> ab >> bw >> bb >> c >> d;
  //printf("%d %d %d %d\n", aw, ab, bw, bb);

  if (c > ab) aw -= c - ab, bw += c - ab, bb += ab, ab = 0;
  else ab -= c, bb += c;
  //printf("%d %d %d %d\n", aw, ab, bw, bb);

  aw += min(d, bw);
  printf("%d\n", aw);
  return 0;
}