v=1;y=v
s=set([v]);n=int(input())
x=[list(map(int,input().split())) for i in range(n)]
a,b=-1<<60,0
c,d=1<<60,0
for i in range(n):
    if a<x[i][0]+x[i][1]*v:
        a=x[i][0]+x[i][1]*v;b=i
    if c>x[i][0]+x[i][1]*v:
        c=x[i][0]+x[i][1]*v;d=i
for _ in range(n):
    q,w=v,2*10**9
    while w-q>1:
        m=(q+w)//2
        e=x[b][0]+x[b][1]*m
        for i in range(n):
            if i!=b and e<x[i][0]+x[i][1]*m:
                w=m;break
        else:
            q=m
    for i in range(n):
        if a<x[i][0]+x[i][1]*w:
            a=x[i][0]+x[i][1]*w;b=i
    s.add(w);v=w;s.add(q)
    q,w=y,2*10**9
    while w-q>1:
        m=(q+w)//2
        e=x[d][0]+x[d][1]*m
        for i in range(n):
            if i!=d and e>x[i][0]+x[d][1]*m:
                w=m;break
        else:
            q=m
    y=w
    for i in range(n):
        if c>x[i][0]+x[i][1]*w:
            c=x[i][0]+x[i][1]*w;d=i
    s.add(y);s.add(q)
ans=1<<60;d=0
for i in list(s):
    a,b=-1<<60,1<<60
    for j,l in x:
        c=j+i*l
        a=max(a,c);b=min(b,c)
    if ans>a-b:
    	ans=a-b;d=i
    elif ans==a-b:
    	d=min(d,i)
print(d)