// TLE

// #pragma GCC target("avx2") // Compile Error?
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <cmath>
#include <iostream>
#include <vector>

constexpr int M = 1000010;

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

    int n;
    std::cin >> n;
    std::vector<std::pair<int, int>> ps(n);
    for (auto &[a, b] : ps) {
        std::cin >> a >> b;
    }

    int max_num = -1;
    int argmax = -1;
    for (int mod = 1; mod <= M; ++mod) {
        int num = 0;
        for (const auto &[a, b] : ps) {
            num += (a % mod) < (b % mod);
        }
        if (num > max_num) {
            max_num = num;
            argmax = mod;
        }
    }
    std::cout << argmax << '\n';
}