#include <bits/stdc++.h> using namespace std; #define endl '\n' #define ll long long void solve(){ int n; cin >> n; vector<array<ll,2>> k(n); map<ll,ll> kk; for(auto& [a,b]:k){ cin >> a >> b; kk[a]+=b; } vector<array<ll,2>> k1; for(auto [l1,r]:kk) k1.push_back({l1,r}); int l=0; ll s=0; ll max1=-1000000000000000000; for(int i=0; i<k1.size(); i++){ s+=k1[i][1]; while(l<i && s-(k1[i][0]-k1[l+1][0])-k1[l][1]>=s-(k1[i][0]-k1[l][0])){ s-=k1[l][0]; l++; } max1=max(max1,s-(k1[i][0]-k1[l][0])); } cout << max1 << endl; } signed main(){ //freopen("input.txt","r",stdin); //freopen("output.txt","w",stdout); ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); int t=1; //cin >> t; while(t--){ solve(); } }