#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
int f(int l, int r, vector<pair<int,int>> &vec, vector<int> &pfx)
{
return pfx[r+1] - pfx[l] - (vec[r].first -vec[l].first);
}
int32_t main()
{
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int n, mxx = INT64_MIN;
int l = 0;
cin>>n;
vector<pair<int,int>> vec(n);
vector<int> pfx(n+1,0);
for (int i = 0; i < n; ++i)
{
cin>>vec[i].first>>vec[i].second;
}
sort(vec.begin(),vec.end());
for (int i = 0; i < n; ++i)
{
pfx[i+1] = pfx[i] + vec[i].second;
}
for (int r = 0; r < n; ++r)
{
while (l < r && f(l,r,vec,pfx) < f(l+1,r,vec,pfx))
++l;
mxx = max(mxx, f(l, r, vec, pfx));
}
//mxx = max(mxx, f(l, r, vec, pfx)); geç artık :(
cout<<mxx<<endl;
return 0;
}
