#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxN = 1e5;
struct Line {
mutable ll k, m, p;
bool operator<(const Line& o) const { return k < o.k; }
bool operator<(ll x) const { return p < x; }
};
struct LineContainer : multiset<Line, less<>> {
// (for doubles, use inf = 1/.0, div(a,b) = a/b)
static const ll inf = LLONG_MAX;
ll div(ll a, ll 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(ll k, ll 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));
}
ll query(ll x) {
assert(!empty());
auto l = *lower_bound(x);
return l.k * x + l.m;
}
};
int n;
ll h[maxN+1], w[maxN+1], dp[maxN+1];
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n;
for (int i = 1; i <= n; ++i) {
cin >> h[i];
}
for (int i = 1; i <= n; ++i) {
cin >> w[i];
w[i] += w[i-1];
}
LineContainer hull;
hull.add(h[1]*2, - h[1]*h[1] + w[1]);
for (int i = 2; i <= n; ++i) {
dp[i] = w[i-1] + h[i]*h[i] - hull.query(h[i]);
hull.add(h[i]*2, - h[i]*h[i] + w[i] - dp[i]);
}
cout << dp[n];
}
