#include <bits/stdc++.h>
#define int long long
using namespace std;
vector<array<int, 3>> adj[100001];
int DP[100001];
map<int, int> DP2[100001], sum[100001];
int32_t main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
//freopen("TEST.in", "r", stdin);
//freopen("TEST.out", "w", stdout);
int n, m;
cin >> n >> m;
for (int i = 0; i < m; i++)
{
int u, v, c, w;
cin >> u >> v >> c >> w;
adj[u].push_back({v, c, w});
adj[v].push_back({u, c, w});
sum[u][c] += w;
sum[v][c] += w;
}
memset(DP, 0x3f, sizeof DP);
DP[1] = 1;
priority_queue<array<int, 3>, vector<array<int, 3>>, greater<>> q;
q.push({DP[1], 1, 0});
while (!q.empty())
{
auto [d, u, pc] = q.top();
//if (pc == 0) cerr << u << " " << pc << " " << d - 1 << endl;
q.pop();
for (const auto& [v, c, w] : adj[u])
{
if (pc == c && DP[v] > DP2[u][c] + sum[u][c] - w)
{
DP[v] = DP2[u][c] + sum[u][c] - w;
q.push({DP[v], v, 0});
}
if (DP[v] > DP[u] + min(w, sum[u][c] - w))
{
DP[v] = DP[u] + min(w, sum[u][c] - w);
q.push({DP[v], v, 0});
}
if (DP2[v][c] > DP[u] || !DP2[v][c])
{
DP2[v][c] = DP[u];
q.push({DP2[v][c], v, c});
}
}
}
if (DP[n] > (int)1e18) cout << -1;
else cout << DP[n] - 1;
return 0;
}
