# https://yukicoder.me/submissions/1039531 を PyPy に移植

n = int(input())
ab = [tuple(map(int, input().split())) for _ in range(n)]
M = 1_000_000

ini = [0] * (M * 2 + 10)
for a, b in ab:
    ini[a + M] += 1
    ini[b + M] -= 1
    ini[a - b + M] -= 1

acc = [0] * (len(ini) + 1)
for i in range(len(ini)):
    acc[i + 1] = acc[i] + ini[i]

def get_sum(l: int, r: int) -> int:
    return acc[min(r, len(ini))] - acc[max(l, 0)]

fs = [0] * (M + 2)
for m in range(2, M + 1):
    for st in range(0, M, m):
        en = st + m
        we = st // m
        fs[m] += (get_sum(st + M, en + M)) * we
        fs[m] += (get_sum(-en + M, -st + M)) * (-we - 1)

argmax = 1
maxval = fs[1]
for i in range(2, M + 1):
    if fs[i] > maxval:
        maxval = fs[i]
        argmax = i
print(argmax)