#pragma GCC optimize("O3") #include <bits/stdc++.h> using namespace std; #define endl '\n' #define int long long #define F first #define S second #define pii pair<int, int> #define pic pair<int, char> #define pci pair<char, int> #define pipii pair<int, pair<int, int>> #define all(v) v.begin(), v.end() #define rall(v) v.rbegin(), v.rend() #define yes() cout << "Yes" << endl #define no() cout << "No" << endl #define gcd __gcd int lcm(int a, int b){ return a / gcd(a , b) * b; } bool isPalindrome(string s){ string x = s; reverse(x.begin(), x.end()); return x == s; } bool isPrime(int n){ if(n < 2) return false; if(n == 2) return true; if(n % 2 == 0) return false; for(int i = 3;i <= sqrt(n);i += 2){ if(n % i == 0) return false; } return true; } int dx[] = {1, -1, 0, 0}; int dy[] = {0, 0, 1, -1}; const int MAX = 1e3 + 5; int dp[MAX][MAX]; mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); signed main() { //freopen("input.txt","r",stdin); //freopen("output.txt","w",stdout); ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); int n; cin >> n; int a[n + 1], b[n + 1]; vector<pii> vt; for(int i = 1;i <= n;i++){ cin >> a[i] >> b[i]; vt.push_back({a[i], b[i]}); } sort(all(vt)); int sum = vt[0].S, x = vt[0].F, y = vt[0].F; int ans = sum - x + y; for(int i = 1;i < vt.size();i++){ sum += vt[i].S; x = max(x, vt[i].F); y = min(y, vt[i].F); ans = max(ans, sum - x + y); } cout << ans << endl; }