//{{{
#include <bits/stdc++.h>
using namespace std;
#define rep(...) repN((__VA_ARGS__,rep3,rep2,loop,~))(__VA_ARGS__)
#define loop(n) rep2(_loop_,n)
#define rep2(i,n) rep3(i,0,n)
#define rep3(i,begin,end) for(int i=(int)(begin),i##_end=(int)(end);i<i##_end;++i)
#define repN(a) repX a
#define repX(a0,a1,a2,x,...) x
typedef long long ll;
const int MOD = 1e9+7;
//}}}

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