#include <bits/stdc++.h>
#define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
#define all(a) a.begin() , a.end()
#define F first
#define S second
using namespace std;
using ll = long long;
#define int ll
const int N = 2e5+5 , inf = 2e9 + 7;
const ll INF = 1e18 , mod = 1e9+7 , P = 6547;
map<int,vector<pair<int,int>>> mp[N];
vector<array<int,3>> g[N];
ll sum[N];
ll mn[N];
void solve(int tc) {
int n, m;
cin >> n >> m;
vector<array<int,4>> vec;
for(int i = 1; i <= m; i ++) {
int a, b,c, p;
cin >> a >> b >> c >> p;
g[a].push_back({b,c,p});
g[b].push_back({a,c,p});
}
set<pair<ll,int>> st;
vector<ll> d(n+1,INF);
fill(mn, mn+m+1, INF);
d[1] = 0;
st.insert({0, 1});
while(st.size()) {
pair<int,int> cur = *st.begin();
st.erase(cur);
int v = cur.S;
for(auto to: g[v]) {
sum[to[1]] += to[2];
mn[to[1]] = min(mn[to[1]], d[to[0]]);
}
for(auto to: g[v]) {
if(cur.F + min(to[2] , sum[to[1]]-to[2]) < d[to[0]]) {
st.erase({d[to[0]], to[0]});
d[to[0]] = cur.F + min(to[2] , sum[to[1]]-to[2]);
st.insert({d[to[0]], to[0]});
}
if(mn[to[1]] + sum[to[1]]-to[2] < d[to[0]]) {
st.erase({d[to[0]], to[0]});
d[to[0]] = mn[to[1]] + sum[to[1]]-to[2];
st.insert({d[to[0]], to[0]});
}
}
for(auto to: g[v]) {
sum[to[1]] = 0;
mn[to[1]] = INF;
}
}
if(d[n] == INF) d[n] = -1;
cout << d[n];
}
/*
*/
main() {
ios;
int tt = 1 , tc = 0;
// cin >> tt;
while(tt --) {
solve(++tc);
}
return 0;
}
