#include <iostream> #include <algorithm> #include <map> #include <set> #include <queue> #include <stack> #include <numeric> #include <bitset> #include <cmath> #include <limits> static const int MOD = 998244353; using ll = long long; using uint = unsigned; using ull = unsigned long long; using namespace std; template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208; int main() { int a, b, c, d, e; cin >> a >> b >> c >> d >> e; a -= b; d -= e; cout << max(a, a+c*d) << "\n"; return 0; }