#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[8]={-1,0,1,0,1,1,-1,-1};
const ll dx[8]={0,-1,0,1,1,-1,1,-1};
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
ll n;
vl a(1010),b(1010);
ll check(ll x){
    ll maxi=-inf,mini=INF;
    rep(i,n){
        chmax(maxi,a[i]+b[i]*x);
        chmin(mini,a[i]+b[i]*x);
    }
    return maxi-mini;
}
int main(){
    cin >> n;
    rep(i,n)cin >> a[i] >> b[i];
    ll left=1,right=inf;
    rep(hoge,50){
        ll m1=(left*2+right)/3;
        ll m2=(left+right*2)/3;
        if(check(m1)>check(m2))left=m1;
        else right=m2;
    }
    ll ans=INF,p=-1;
    for(int i=left-100;i<=left+100;i++){
        if(i<=0)continue;
        if(chmin(ans,check(i)))p=i;
    }
    cout << p <<endl;
}