#include <iostream>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <algorithm>
#include <climits>
#include <cmath>
#include <numeric>
#include <string>
#include <bitset>
#include <assert.h>
#include <iomanip>
using namespace std;
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
 
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
*/
template <typename T>
using pqg = priority_queue<T, vector<T>, greater<T>>;

const long long infl = 4e18;
const int inf = 1e9;
const int mod1 = 1e9 + 7;
const int mod2 = 998244353;

void solve()
{
	int n;
	cin >> n;
	vector<pair<long long, long long>> a(n);
	for(auto &[f, s]: a)
		cin >> f >> f >> s;
	map<long long, long long> mp;
	for(auto [f, s]: a)
		mp[f] = max({mp[f], f, s});
	vector<pair<long long, long long>> b;
	for(auto [f, s]: mp)
		b.push_back({f, s});
	long long res = 0, lst = 0;
	int m = (int)b.size();
	for(int i = 0; i < m; i++)
	{
		res += llabs(lst - b[i].first);
		lst = b[i].first;
		res = max(res, b[i].second);
	}
	cout << res;
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int t = 1;
	// cin >> t;

	while (t--)
	{
		solve();
		cout << (t ? "\n" : "");
	}
}