#include<bits/stdc++.h>
using namespace std;


int main() {
	int R, B, C, D, E;
	cin >> R >> B >> C >> D >> E;
	int res1 =  (R * C + B * D);
	int res2 = 0;
	if (R > B) {
		res2 = R * E * 2 + (R-B) * C;
	}
	else if (R <= B) {
		res2 = R * E * 2 + (B-R) * D;
	}
	cout << max(res1, res2);
	return 0;
}