#include "bits/stdc++.h"
using namespace std;
#ifdef _DEBUG
#include "dump.hpp"
#else
#define dump(...)
#endif

#define int long long
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define all(c) begin(c),end(c)
const int INF = sizeof(int) == sizeof(long long) ? 0x3f3f3f3f3f3f3f3fLL : 0x3f3f3f3f;
const int MOD = 1'000'000'007;
template<class T> bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool chmin(T &a, const T &b) { if (b < a) { a = b; return true; } return false; }


signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	int N; cin >> N;
	vector<int> a(N), b(N); rep(i, 0, N) {
		cin >> a[i] >> b[i];
	}

	// 三分探索
	auto f = [&](double x) {
		double maxi = -INF, mini = INF;
		rep(i, 0, N) {
			chmax(maxi, a[i] + b[i] * x);
			chmin(mini, a[i] + b[i] * x);
		}
		return maxi - mini;
	};
	auto ternarySearch = [&](double l, double r) {
		for (int i = 0; i < 1000; i++) {
			double m1 = l + (r - l) / 3, m2 = r - (r - l) / 3;
			// min 下に凸 : f(m1) > f(m2)
			// max 上に凸 : f(m1) < f(m2)
			if (f(m1) > f(m2)) {
				l = m1;
			}
			else {
				r = m2;
			}
		}
		return r;
	};
	double x = ternarySearch(0, INF);
	auto g = [&](int x) {
		int maxi = -INF, mini = INF;
		rep(i, 0, N) {
			chmax(maxi, a[i] + b[i] * x);
			chmin(mini, a[i] + b[i] * x);
		}
		return maxi - mini;
	};
	dump(x);
	int mini = INF;
	int ans = -1;
	rep(i, max((int)(x - 1), 1LL), max((int)(x + 2), 2LL)) {
		if (chmin(mini, g(i))) {
			ans = i;
		}
	}
	cout << ans << endl;
	return 0;
}