M = off = 1012345

cum = [0] * 2 * M


def get_sum(l, r):
    l += off
    r += off
    return cum[min(2 * M - 1, r)] - cum[max(l, 0)]


N = int(input())
for i in range(N):
    a, b = map(int, input().split())
    cum[a + off + 1] += 1
    cum[b + off + 1] -= 1
    cum[a - b + off + 1] -= 1

for i in range(1, M * 2):
    cum[i] += cum[i - 1]

ans = [-1] * M
for m in range(1, M):
    val = 0
    r = 0
    while r < M:
        val += get_sum(r, r + m) * (r // m)
        r += m
    l = -m
    while l > -M:
        val += get_sum(l, l + m) * (l // m)
        l -= m
    ans[m] = val

print(ans.index(max(ans)))