# correct

M = 10**6 + 10

n = int(input())
# -M, ..., -1, 0, 1, ..., M
# c[i] = weight of i - M
c = [0] * (2 * M + 1)

for _ in range(n):
    a, b = map(int, input().split())
    c[M + a] += 1
    c[M + b] -= 1
    c[M + a - b] -= 1

# prefix sum
c.insert(0, 0)
for i in range(2 * M + 1):
    c[i + 1] += c[i]

max_f, argmax = -1, 0
for m in range(1, M):
    # max{k | k * m <= M}
    max_k = M // m
    f_m = -n * max_k
    # sum C(-tm), ..., C(-m), C(0), C(m), ..., C(tm)
    for k in range(-max_k, max_k + 1):
        f_m -= c[M + k * m]
    if f_m > max_f:
        max_f, argmax = f_m, m
print(argmax)