///*** Sown_Vipro ***///
/// ->GIAI BA QUOC GIA<- ///
#include<bits/stdc++.h>
using namespace std;
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("popcnt")
#define F first
#define S second
#define pb push_back
#define ll long long
#define pi pair<int, int>
#define pii pair<int, pair<int, int> >
#define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
#define out(name) if(fopen(name, "w")) freopen(name, "w", stdout);
#define szz(s) int(s.size())
#define int long long
const int N = 1e6 + 5, MAX = 1e6, oo = 1e9 + 5, MOD = 1e9 + 7;
int n;
int h[N], w[N];
long long s[N], dp[N];
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;
}
} hull;
void solve(){
cin >> n;
for(int i = 1; i <= n; ++i){
cin >> h[i];
}
for(int i = 1; i <= n; ++i){
cin >> w[i];
s[i] = s[i - 1] + w[i];
}
for(int i = 2; i <= n; ++i) dp[i] = 1e18;
hull.add(2 * h[1], -(dp[1] + h[1] * h[1] - s[1]));
for(int i = 2; i <= n; ++i){
dp[i] = -hull.query(h[i]) + h[i] * h[i] + s[i - 1];
hull.add(2 * h[i], -(dp[i] + h[i] * h[i] - s[i]));
}
cout << dp[n];
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
inp("in.txt");
int t = 1;
// cin >> t;
while(t--){
solve();
}
}
