#include<bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
void __print(int x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef local
void setio(){freopen("/Users/iantsai/Library/Mobile Documents/com~apple~CloudDocs/cpp/Empty.md","r",stdin);}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
void setIO(string s) {
freopen((s + ".in").c_str(), "r", stdin);
freopen((s + ".out").c_str(), "w", stdout);
}
struct line{
int a,b;
int operator()(const int x)const{
return a*x+b;
}
};
bool check(line l1,line l2,line l3){
return (l3.b-l2.b)*(l1.a-l2.a)<=(l2.b-l1.b)*(l2.a-l3.a);
}
const int mxn=5e5+5;
int seg[4*mxn],prefix[mxn],tag[4*mxn];
pii v[mxn];
void push(int id){
seg[id*2]-=tag[id];
seg[id*2+1]-=tag[id];
tag[id*2]+=tag[id];
tag[id*2+1]+=tag[id];
tag[id]=0;
}
void build(int l,int r,int id){
if(l==r){
seg[id]=prefix[l]-v[l].F;
return;
}
int mm=l+r>>1;
build(l,mm,id*2);
build(mm+1,r,id*2+1);
seg[id]=max(seg[id*2],seg[id*2+1]);
}
void modify(int l,int r,int id,int ql,int qr,int v){
if(ql<=l and r<=qr){
seg[id]-=v;
tag[id]=v;
return;
}
int mm=l+r>>1;
push(id);
if(qr<=mm){
modify(l,mm,id*2,ql,qr,v);
}
else if(ql>mm){
modify(mm+1,r,id*2+1,ql,qr,v);
}
else{
modify(l,mm,id*2,ql,mm,v);
modify(mm+1,r,id*2+1,mm+1,qr,v);
}
seg[id]=max(seg[id*2],seg[id*2+1]);
}
int query(int l,int r,int id,int ql,int qr){
if(ql<=l and r<=qr){
return seg[id];
}
int mm=l+r>>1;
push(id);
if(qr<=mm){
return query(l,mm,id*2,ql,qr);
}
else if(ql>mm){
return query(mm+1,r,id*2+1,ql,qr);
}
else{
return max(query(l,mm,id*2,ql,mm),query(mm+1,r,id*2+1,mm+1,qr));
}
}
signed main(){
setio();
ios::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
int n;
cin>>n;
for(int i=1;i<=n;i++){
cin>>v[i].F>>v[i].S;
}
sort(v+1,v+n+1);
for(int i=1;i<=n;i++){
prefix[i]=prefix[i-1]+v[i].S;
}
build(1,n,1);
int ans=0;
for(int i=1;i<=n;i++){
chmax(ans,query(1,n,1,i,n)-prefix[i-1]+v[i].F);
}
cout<<ans<<'\n';
}
/*
input:
*/
