// yukicoder: 149 碁石の移動
// 2019.5.19 bal4u

#include <stdio.h>

int main()
{
	int Aw, Ab, Bw, Bb, C, D;
	
	scanf("%d%d%d%d%d%d", &Aw, &Ab, &Bw, &Bb, &C, &D);
	if (C <= Ab) Bb += C, Ab -= C;
	else Bb += Ab, Bw += C-Ab, Aw -= C-Ab, Ab = 0; 
	if (D <= Bw) Aw += D, Bw -= D;
	else Aw += Bw, Ab += D-Bw, Bb -= D-Bw, Bw = 0;
	printf("%d\n", Aw);
	return 0;
}