#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define mp make_pair
#define ull unsigned long long
using namespace std;
ll binpow (ll a, ll b){
if (b == 0) return 1;
if (b & 1) return binpow(a, b - 1) * a;
else return binpow(a, b / 2) * binpow(a, b / 2);
}
ll gcd(ll a, ll b){
return (b ? gcd(b, a % b) : a);
}
ll nums(ll g){
ll cur = 0;
while(g){
cur++, g /= 10;
}
return cur;
}
bool comp(pair <ll, ll> a, pair <ll, ll> b){
if (a.first == b.first){
return a.second < b.second;
}
else return a.first < b.first;
}
ll get1(ll q, ll g){
ll cur = 1;
for (ll i = q; i > g; i--){
cur *= i;
}
return cur;
}
const ll mod = (ll)998244353;
ll n, k, x, y;
pair <ll, ll> p[200005];
vector <ll> v;
bool used[100][5];
int main(){
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
cin >> n;
for (ll i = 1; i <= n; i++){
cin >> x >> y;
p[i] = {x, y};
}
sort (p + 1, p + n + 1, comp);
ll pref[n + 1];
pref[0] = 0;
for (ll i = 1; i <= n; i++){
pref[i] = pref[i - 1] + p[i].second;
}
ll l = 1, r = n, mx = (ll)-1e15;
while(l <= r){
mx = max(mx, (pref[r] - pref[l - 1]) - (p[r].first - p[l].first));
if ((pref[r - 1] - pref[l - 1]) - (p[r - 1].first - p[l].first) >= (pref[r] - pref[l]) - (p[r].first - p[l + 1].first)){
r--;
}
else l++;
}
cout << mx;
return 0;
}
/**
6
4 1
1 5
10 3
9 1
4 2
5 3
1 5
4 1
4 2
5 3
9 1
10 3
6
4
7
*/
