#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], b[n]; for(int i = 0;i < n;i++){ cin >> a[i] >> b[i]; } int ans = 0; for(int mask = 1;mask < (1 << n);mask++){ vector<pii> vt; for(int i = 0;i < n;i++){ if(mask & (1 << i)) vt.push_back({a[i], b[i]}); } int x = INT_MIN, y = INT_MAX; int sum = 0; for(auto &[l, r] : vt){ sum += r; x = max(x, l); y = min(y, l); } ans = max(ans, sum - (x - y)); } cout << ans << endl; }