n = int(input())
m = 1000010
cnt = [0] * (2 * m + 1)
for _ in range(n):
    a, b = map(int, input().split())
    cnt[a + m] -= 1
    cnt[b + m] += 1
    cnt[(b - a - 1) + m] -= 1


cum = [0] * (2 * m + 1)
for i in range(1, 2 * m + 1):
    cum[i] = cum[i - 1] + cnt[i]

ans = [0] * m
for i in range(1, m):
    t = 0
    for l in range(0, m, i):
        r = min(m, l + i)
        ans[i] += (cum[r - 1 + m] - cum[l - 1 + m]) * t
        t += 1
    t = -1
    for r in range(0, -m, -i):
        l = max(-m + 1, r - i)
        ans[i] += (cum[r - 1 + m] - cum[l - 1 + m]) * t
        t -= 1


print(ans[1:].index(min(ans[1:m])) + 1)