#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 solve() {
ll dp[n][m + 1][2];
for (int i = 0; i < n; i++) {
for (int j = 0; j <= m; j++) {
dp[i][j][0] = dp[i][j][1] = -INF;
}
}
priority_queue<tuple<ll, int, int, bool>> pq;
dp[0][0][0] = 0;
pq.push({0, 0, 0, 0});
while (not pq.empty()) {
auto [dist, u, flipped, returning] = pq.top();
pq.pop();
if (dp[u][flipped][returning] != dist) continue;
// cout << u << ' ' << flipped << ' ' << returning << ' ' << dist << endl;
for (int e : g[u]) {
auto [a, b, c, d] = edges[e];
ll incur = -c;
if (flipped == e) swap(a, b);
if (dist + incur > dp[b][flipped][returning | b == n - 1]) {
dp[b][flipped][returning | b == n - 1] = dist + incur;
pq.push({dist + incur, b, flipped, returning | b == n - 1});
}
if (flipped or returning) continue;
incur = -d;
if (dist + incur > dp[u][e][returning]) {
dp[u][e][returning] = dist + incur;
pq.push({dist + incur, u, e, returning});
}
}
}
ll ans = INF;
for (int i = 0; i <= m; i++) {
ans = min(ans, -dp[0][i][1]);
}
return (ans != INF ? ans : -1);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m;
g.resize(n), edges.resize(m + 1);
for (int i = 1; i <= m; i++) {
auto &[u, v, c, d] = edges[i];
cin >> u >> v >> c >> d;
u--, v--;
g[u].push_back(i);
g[v].push_back(i);
}
cout << solve() << '\n';
return 0;
}
