def solve():
    N = int(input())
    A = [0] * N
    B = [0] * N
    for i in range(N):
        A[i], B[i] = list(map(int, input().split()))

    a = 1
    b = max(A) + 1

    def f(x):
        ls = [A[i] + B[i] * x for i in range(N)]
        return max(ls) - min(ls)

    for i in range(52):
        c1 = (b - a) // 3 + a
        c2 = (b - a) // 3 * 2 + a

        fc1 = f(c1)
        fc2 = f(c2)

        if fc1 < fc2:
            b = c2
        else:
            a = c1

    print((a + b) // 2)


def main():
    solve()


if __name__ == '__main__':
    main()