#include <climits>
#include <functional>
#include <iostream>
#include <queue>
#include <set>
#include <vector>
int main() {
std::cin.tie(NULL)->sync_with_stdio(false);
int n;
std::cin >> n;
// ans = sum abs(prefix(a - c, i)) where c[] = final configuration
// c[i] = b[i] + x[i], where x[i] = some fertilizers we remove from position i
// so ans = sum abs(prefix(a - b, i) - prefix(x, i)) and we want to minimize this
// DP[i][x] = minimize ans with x = prefix(x, i)
// DP[i][x] = min(DP[i-1][y] + abs(prefix(a - b, i) - x, 0 <= x - y <= a[i])
// - here x = prefix(x, i) and y = prefix(x, i-1), and x[i] = x - y
// - range x[i] is [0, a[i]] -> 0 <= x - y <= a[i]
// Transform DP: DP[i][x] = min(DP[i-1][y], max(0, x-a[i]) <= y <= x) + abs(prefix(a - b, i) - x)
// we can do slope trick here as inductively it is convex linear
long long total = 0;
long long m = 0, c = 0; // leftmost m & c
long long shift = 0;
std::priority_queue<long long> pq_neg;
std::priority_queue<long long, std::vector<long long>, std::greater<long long>> pq_pos;
for (int i = 0; i < n; i++) {
long long a, b;
std::cin >> a >> b;
total += a - b;
// take min: shift positive grad all by a
if (!pq_pos.empty()) {
shift += a;
}
// insert
if (total > 0) {
// combine with y = total - x
m--;
c += total;
pq_neg.push(total);
pq_pos.push(total - shift);
} else {
// combine with y = x + (-total) if x >= 0, else -x -total
m--;
c += -total;
pq_neg.push(0);
pq_pos.push(-shift);
}
// normalize
while (pq_neg.top() > pq_pos.top() + shift) {
long long x_neg = pq_neg.top();
long long x_pos = pq_pos.top() + shift;
pq_neg.pop();
pq_pos.pop();
pq_neg.push(x_pos);
pq_pos.push(x_neg - shift);
}
}
// reorder pq_neg
std::vector<long long> xs(pq_neg.size());
while (!pq_neg.empty()) {
long long x = pq_neg.top();
pq_neg.pop();
xs[pq_neg.size()] = x;
}
for (long long x: xs) {
if (x > total) {
std::cout << m * total + c << std::endl;
return 0;
}
m++;
c -= x;
}
while (!pq_pos.empty()) {
long long x = pq_pos.top() + shift;
pq_pos.pop();
if (x > total) {
std::cout << m * total + c << std::endl;
return 0;
}
m++;
c -= x;
}
std::cout << m * total + c << std::endl;
return 0;
}
