#include <bits/stdc++.h>
using namespace std;
using ll = long long int;
const ll mod = 1e9 + 7;
vector<ll> pf;
vector<pair<ll,ll>> v;
ll sum(int l, int r){
if(l == 0) return pf[r];
return pf[r] - pf[l - 1];
}
ll eval(int l, int r){
if(l > r) return -1;
return sum(l, r)- (v[r].first - v[l].first);
}
int main(){
int n;
cin >> n;
vector<pair<ll, ll>> temp(n);
for(auto& i : temp){
cin >> i.first >> i.second;
}
sort(begin(temp), end(temp));
int i = 0;
while(i < n){
ll s = temp[i].second;
while(i + 1 < n && temp[i + 1].first == temp[i].first){
++i;
s += temp[i].second;
}
v.push_back({temp[i].first, s});
++i;
}
sort(begin(v), end(v));
n = v.size();
pf.resize(n);
pf[0] = v[0].second;
for(int i = 1; i < n; ++i){
pf[i] = pf[i - 1] + v[i].second;
}
ll sol = 0;
int l = 0, r = 0;
while(r < n){
while(l < r && eval(l + 1, r) > eval(l, r)){
++l;
}
sol = max(sol, eval(l, r));
++r;
}
cout << sol << endl;
return 0;
}
