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

const int maxN = 1000;
const int inf = 1e9 + 20;

int cnt;
std::vector<std::pair<int, int>> vec;
int dp[maxN][maxN][2], was[maxN][maxN][2];

int get(int left, int right, int pos) {
	if (left == right) {
		return 0;
	}
	if (was[left][right][pos]) return dp[left][right][pos];
	was[left][right][pos] = 1;
	int& ans = dp[left][right][pos];
	if (pos == 0) {
		auto leftAns = get(left + 1, right, 0) + vec[left + 1].first - vec[left].first;
		auto rightAns = get(left + 1, right, 1) + vec[right].first - vec[left].first;
		if (leftAns <= vec[left].second) {
			ans = std::min(ans, leftAns);
		}
		if (rightAns <= vec[right].second) {
			ans = std::min(ans, rightAns);
		}
	} else {
		auto leftAns = get(left, right - 1, 0) + vec[right].first - vec[left].first;
		auto rightAns = get(left, right - 1, 1) + vec[right].first - vec[right - 1].first;
		if (leftAns <= vec[right].second) {
			ans = std::min(ans, leftAns);
		}
		if (rightAns <= vec[right].second) {
			ans = std::min(ans, rightAns);
		}
	}
	return ans;
}

int main() {
    std::ios::sync_with_stdio(0);
    std::cin.tie(0);
    std::cout.tie(0);
    std::cin >> cnt;
    vec.resize(cnt);
    for (int i = 0; i < cnt; i++) {
    	int dist, time;
    	std::cin >> dist >> time;
    	vec[i] = {dist, time};
    }
    std::sort(vec.begin(), vec.end());
    for (int i = 0; i < cnt; i++)
    	for (int j = 0; j < cnt; j++) {
    		dp[i][j][0] = dp[i][j][1] = inf;
		}
    auto ans = std::min(get(0, cnt - 1, 0), get(0, cnt - 1, 1));
    if (ans < inf) {
    	std::cout << ans;
    } else {
    	std::cout << "No solution";
    }
    return 0;
}