#include "math.h"
#include <algorithm>
#include <complex>
#include <cstdio>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <string>
#include <vector>
#define ifor(i, a, b) for (int i = (a); i < (b); i++)
#define rfor(i, a, b) for (int i = (b)-1; i >= (a); i--)
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rrep(i, n) for (int i = (n)-1; i >= 0; i--)
#define INF 1e18
using namespace std;
typedef long double ld;
typedef long long int lli;
typedef complex<double> P;
const double eps = 1e-11;
int vex[4] = {1, 0, -1, 0};
int vey[4] = {0, 1, 0, -1};
typedef vector<double> Vec;
typedef vector<int> vec;
typedef vector<Vec> MAT;
typedef vector<vec> mat;
lli MOD = 1000000007;
int N;
lli a[1001], b[1001];
lli f(lli A, lli B, lli x)
{
    return (A + B * x);
}
lli fx(lli x)
{
    lli c = -INF, d = INF;
    rep(i, N) c = max(c, f(a[i], b[i], x));
    rep(i, N) d = min(d, f(a[i], b[i], x));
    return c - d;
}
int main()
{
    cin >> N;
    rep(i, N) cin >> a[i] >> b[i];
    lli up = 1e9, low = -1;
    rep(i, 100)
    {
        lli t31 = (up + 2 * low) / 3, t32 = (up * 2 + low) / 3;
        if (fx(t31) > fx(t32))
            low = t31;
        else
            up = t32;
    }

    lli ans = low;
    rep(i, 4)
    {
        if (fx(ans) > fx(low + i))
            ans = low + i;
    }
    if (ans <= 0)
        ans = 1;
    printf("%d\n", ans);
}