N = int(raw_input())
ab = [map(int, raw_input().split()) for i in xrange(N)]

candx = set([1])
for i in xrange(N):
    a1, b1 = ab[i]
    for j in xrange(i+1, N):
        a2, b2 = ab[j]
        if b2-b1 == 0:
            continue
        x = abs((a1-a2)/(b1-b2))
        if x >  0: candx.add(x)
        if x >= 0: candx.add(x+1)
        if x >  1: candx.add(x-1)

ax, mn = 0, 10**50
for x in candx:
    abx = [a+b*x for a,b in ab]
    tmp = max(abx) - min(abx)
    if tmp < mn:
        mn = tmp
        ax = x
    if tmp == mn:
        ax = min(x, ax)
print ax