#include <iostream>
#include <string>
#include <queue>
#include <vector>
#include <algorithm>
#include <utility>
using namespace std;

struct Edge {
	long long end;
	long long cmp;
	long long points;
};

long long N, M, K;

long long djikstra(long long s, vector<vector<Edge>>& graph) {
	priority_queue<pair<long long, long long>, vector<pair<long long, long long>>, less<pair<long long, long long>>> q;
	vector<bool> visited(N);
	vector<long long> dist(N);
	dist[s] = 0;
	q.push({ 0, s });
	while (!q.empty()) {
		auto c = q.top();
		q.pop();

		visited[c.second] = true;
		for (Edge& e : graph[c.second]) {
			if (visited[e.end]) continue;
			long long nd = dist[c.second] + e.cmp;
			if (dist[e.end] == 0 || nd > dist[e.end]) {
				dist[e.end] = nd;
				q.push({ nd, e.end });
			}
		}
	}
	return dist[N-1];
}

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

	cin >> N >> M >> K;
	vector<vector<Edge>> graph(N, vector<Edge>());
	for (long long i = 0; i < M; i++) {
		long long k1, k2, pi, ti;
		cin >> k1 >> k2 >> pi >> ti;
		k1--; k2--;
		graph[k1].push_back({ k2, pi - ti, pi });
		graph[k2].push_back({ k1, pi - ti, pi });
	}
	cout << K + djikstra(0, graph);
}