#include <iostream>
#include <algorithm>
#include <vector>
#include <utility>

using std::vector;
using std::cin;
using std::cout;
using std::pair;

int dp[1111][1111][2] = {};

int main() {
	int num;
	cin >> num;
	int inf = 111111111;
	vector<pair<int, int> > values;
	for (int i = 0; i < num; ++i) {
		int pos, time;
		cin >> pos >> time;
		values.push_back({ pos, time });
	}
	std::sort(values.begin(), values.end());
	for (int i = 0; i < num; ++i) {
		for (int j = 0; j < num; ++j) {
			dp[i][j][0] = inf;
			dp[i][j][1] = inf;
			if (i == j) {
				dp[i][j][0] = dp[i][j][1] = 0;
			}
		}
	}

	for (int i = 0; i < num; ++i) {
		for (int j = i + 1; j < num; ++j) {
			if (j > 0 && values[j].second >= dp[i][j - 1][1] + abs(values[j].first - values[j - 1].first)) {
				dp[i][j][1] = std::min(dp[i][j][1], dp[i][j - 1][1] + abs(values[j].first - values[j - 1].first));
			}
		}
	}

	for (int i = num - 2; i >= 0; --i) {
		for (int j = i + 1; j < num; ++j) {
			if (i + 1 < num && values[i].second >= dp[i + 1][j][0] + abs(values[i].first - values[i + 1].first)) {
				dp[i][j][0] = std::min(dp[i][j][0], dp[i + 1][j][0] + abs(values[i].first - values[i + 1].first));
			}
		}
	}
	cout << std::min(dp[0][num - 1][0], dp[0][num - 1][1]);
	return 0;
}