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

template <class T>
std::vector<T> vec(int len, T elem) { return std::vector<T>(len, elem); }

void solve() {
    int n;
    std::cin >> n;

    std::vector<std::pair<int, int>> ps(n);
    for (auto& p : ps) {
        int a, b;
        std::cin >> a >> b;
        p = std::make_pair(a, b - a);
    }

    int ok = 2000, ng = 0;
    while (ok - ng > 1) {
        int mid = (ok + ng) / 2;

        std::vector<std::vector<int>> graph(n);
        for (int v = 0; v < n; ++v) {
            for (int u = 0; u < n; ++u) {
                if (u == v || ps[v].second + ps[u].first > mid) continue;
                graph[v].push_back(u);
            }
        }

        auto dp = vec(n, vec(1 << n, false));
        for (int i = 0; i < n; ++i) {
            dp[i][1 << i] = true;
        }

        for (int b = 0; b < (1 << n); ++b) {
            for (int i = 0; i < n; ++i) {
                if (!dp[i][b]) continue;

                for (auto j : graph[i]) {
                    if ((b >> j) & 1) continue;
                    dp[j][b | (1 << j)] = true;
                }
            }
        }

        if (std::any_of(dp.begin(), dp.end(),
                        [](const auto& v) { return v.back(); })) {
            ok = mid;
        } else {
            ng = mid;
        }
    }

    std::cout << ok << "\n";
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}