#include <bits/stdc++.h>
using namespace std;
inline namespace
{
struct Line
{
mutable long k, m, p;
bool operator<(const Line &o) const { return k < o.k; }
bool operator<(long x) const { return p < x; }
};
struct LineContainer : multiset<Line, less<>>
{
// (for doubles, use inf = 1/.0, div(a,b) = a/b)
static const long inf = LONG_MAX;
long div(long a, long b)
{ // floored division
return a / b - ((a ^ b) < 0 && a % b);
}
bool isect(iterator x, iterator y)
{
if (y == end())
return x->p = inf, 0;
if (x->k == y->k)
x->p = x->m > y->m ? inf : -inf;
else
x->p = div(y->m - x->m, x->k - y->k);
return x->p >= y->p;
}
void add(long k, long m)
{
auto z = insert({k, m, 0}), y = z++, x = y;
while (isect(y, z))
z = erase(z);
if (x != begin() && isect(--x, y))
isect(x, y = erase(y));
while ((y = x) != begin() && (--x)->p >= y->p)
isect(x, erase(y));
}
long query(long x)
{
assert(!empty());
auto l = *lower_bound(x);
return l.k * x + l.m;
}
};
} // namespace
void solve()
{
int n;
cin >> n;
vector<long> h(n), w(n);
for (long &x : h)
cin >> x;
for (long &x : w)
cin >> x;
long add = 0;
for (long x : w)
add += x;
vector<long> dp(n);
LineContainer cht;
dp[0] = w[0];
cht.add(2 * h[0], dp[0] - h[0] * h[0]);
for (int i = 1; i < n; i++)
{
dp[i] = cht.query(h[i]) - h[i] * h[i] + w[i];
cht.add(2 * h[i], dp[i] - h[i] * h[i]);
}
cout << -dp[n - 1] + add << '\n';
}
int main()
{
ios_base::sync_with_stdio(false), cin.tie(NULL);
solve();
return 0;
}
