#include <iostream>
#include <vector>
#include <queue>
#include <tuple>
using namespace std;
using ll = long long;
const ll INF = 1e18;
int n, m;
vector<tuple<int, int, ll, ll>> edges;
vector<vector<int>> g;
ll bfs(int start, int flipped) {
ll dp[n];
for (int i = 0; i < n; i++) {
dp[i] = -INF;
}
priority_queue<tuple<ll, int>> pq;
dp[start] = 0;
pq.push({0, start});
while (not pq.empty()) {
auto [dist, u] = pq.top();
pq.pop();
if (dp[u] != dist) continue;
for (int e : g[u]) {
auto [a, b, c, d] = edges[e];
if (flipped == e) swap(a, b);
if (dist - c > dp[b]) {
dp[b] = dist - c;
pq.push({dist - c, b});
}
}
}
return -dp[start ? 0 : n - 1];
}
ll solve(int flipped) {
return bfs(0, flipped) + bfs(n - 1, flipped) + get<3>(edges[flipped]);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m;
g.resize(m), edges.resize(m + 1);
auto &[a, b, c, d] = edges[0];
a = b = -1;
c = d = 0;
for (int i = 1; i <= m; i++) {
auto &[a, b, c, d] = edges[i];
cin >> a >> b >> c >> d;
a--, b--;
g[a].push_back(i);
g[b].push_back(i);
}
ll ans = INF;
for (int i = 0; i <= m; i++) {
ans = min(ans, solve(i));
}
cout << (ans != INF ? ans : -1) << '\n';
return 0;
}
