#include <bits/stdc++.h>
#define endl '\n'
typedef long long ll;
struct slope_trick {
const ll inf = 9223372036854775807ll;
std::multiset < ll > left_set, right_set;
ll height;
slope_trick() {
height = 0;
}
ll get_right() {
if (right_set.empty()) return inf;
return *right_set.begin();
}
ll get_left() {
if (left_set.empty()) return -inf;
return *left_set.rbegin();
}
void add_basic(ll v) {
ll left = get_left(), right = get_right();
if (v >= left && v <= right) {
left_set.insert(v);
right_set.insert(v);
}
else {
if (v < left) {
left_set.insert(v);
left_set.insert(v);
right_set.insert(left);
left_set.erase(left_set.find(left));
height = height + abs(v - left);
}
else {
assert(false);
}
}
}
void prefix_minimum() {
right_set.clear();
}
ll query_vlaue(ll debit) {
ll last = get_left(), slope = 0, base = height;
while(left_set.size() > 0 && get_left() > debit) {
base = base + (last - get_left()) * slope;
slope++;
last = get_left();
left_set.erase(left_set.find(last));
}
if (slope != 0) {
base = base + (last - debit) * slope;
}
return base;
}
};
const int maxn = 500010;
int n;
ll a[maxn], b[maxn];
ll x[maxn], pref[maxn];
void solve() {
std::cin >> n;
for (int i = 1; i <= n; i++) {
std::cin >> a[i] >> b[i];
x[i] = a[i] - b[i];
pref[i] = pref[i - 1] + x[i];
}
slope_trick st;
for (int i = 1; i <= n; i++) {
if (pref[i] < 0) {
st.height += -pref[i];
st.add_basic(0);
}
else {
st.add_basic(pref[i]);
}
st.prefix_minimum();
}
ll ans = st.query_vlaue(pref[n]);
std::cout << ans << endl;
}
void speed()
{
std::ios_base::sync_with_stdio(false);
std::cin.tie(NULL);
std::cout.tie(NULL);
}
signed main()
{
speed();
solve();
return 0;
}
