#include <stdio.h>
#include <iostream>
#include <math.h>
#include <vector>
#include <algorithm>

int main() {

  int aw, ab;
  int bw, bb;
  int c, d;
  
  std::cin >> aw >> ab;
  std::cin >> bw >> bb;

  std::cin >> c >> d;

  if( c <= ab ) {
    ab -= c;
    bb += c;
  }
  else {
    bb += ab;
    aw -= (c - ab);
    bw += (c - ab);
    ab = 0;    
  }

  if( d <= bw ) {
    aw += d;
    bw -= d;
  }
  else {
    aw += bw;
    ab += (d - bw);
    bb -= (d - bw);
    bw = 0;    
  }

  std::cout << aw << std::endl;

  return 0;
}