#include<stdio.h>
int main()
{
	long long int r, p, q;
	scanf("%lld %lld %lld", &r, &p, &q);
	long long int a, b, c, d;
	scanf("%lld %lld %lld %lld", &a, &b, &c, &d);
	long long int res, val;
	long long int min, mid, max;
	min = 0;
	max = 1000000001;
	while (max - min > 1)
	{
		mid = (max + min) / 2;
		res = d;
		res += a - mid;
		res += b - mid;
		res += c - mid;
		if (res < 0)
		{
			max = mid;
			continue;
		}
		val = 0;
		if (a < mid)
			val += mid - a;
		if (b < mid)
			val += mid - b;
		if (c < mid)
			val += mid - c;
		val *= q;
		val += mid * p;
		if (val > r)
			max = mid;
		else
			min = mid;
	}
	printf("%lld\n", min);
	return 0;
}