ZeptoLab Code Rush 2015 C. Om Nom and Candies

#define _CRT_SECURE_NO_WARNINGS 
#include<iostream>
#include<algorithm>
#include<string>
#include<sstream>
#include<set>
#include<vector>
#include<stack>
#include<map>
#include<queue>
#include<deque>
#include<cstdlib>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<ctime>
#include<functional>
using namespace std;

typedef long long ll;
ll C, hr, wr, hb, wb;
int main()
{
	//freopen("t.txt", "r", stdin);
	while (cin >> C >> hr >> hb >> wr >> wb)
	{
		ll ans = 0;
		for (ll i = 0; i < 100000; i++)
		{
			if (i*wr <= C)
				ans = max(ans, i*hr + (C - wr*i) / wb*hb); 
			if (i*wb <= C)
				ans = max(ans, i*hb + (C - wb*i) / wr*hr);
		}
		cout << ans << endl;
	}
	return 0;
}