#!/usr/bin/env python
# -*- coding: utf-8 -*-
from math import ceil
from math import floor

def f(x):
    max_f = -1
    min_f = 10**20
    for a,b in AB:
        max_f = max(max_f, a + b * x)
        min_f = min(min_f, a + b * x)
    return max_f - min_f


N = int(input())
AB = [list(map(int,input().split())) for i in range(0,N)]

left = 1
right = 10**10
eps = 1e-6

for i in range(100):
    y1 = f((left * 2 + right)/3)
    y2 = f((left+ right * 2)/3)

    if y1 <= y2 + eps:
        right = (left + right * 2)/3
    else:
        left = (left * 2 + right)/3

if f(ceil(left)) < f(floor(left)):
    c = ceil(left)
else:
    c = floor(left)

ans = 0
min_f = 10**20
for i in range(max(1,c - 30), min(c + 31, 10**9 + 1)):
    if f(i) < min_f:
        ans = i
        min_f = f(i)
print(ans)