#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 5e5 + 100;
struct s {
int x, y, l, c;
} e[N];
int p[N];
vector<pair<int, int>> g[N];
int dis[N];
bool vis[N];
int n, m, ans;
int dijk(int st, int ed, int d) {
priority_queue<pair<int, int>> q;
memset(dis, 0x3f, sizeof(dis));
memset(vis, false, sizeof(vis));
dis[st] = 0;
q.push({0, st});
while (q.size()) {
int loc = q.top().second;
q.pop();
if (vis[loc]) continue;
vis[loc] = true;
for (auto i : g[loc]) {
int to = i.first;
int l = i.second;
if (vis[to]) continue;
if (dis[to] > dis[loc] + l) {
dis[to] = dis[loc] + l;
q.push({-dis[to], to});
}
}
}
return d < dis[ed];
}
int find(int x) {
if (x == p[x]) return x;
p[x] = find(p[x]);
return p[x];
}
bool cmp(s a, s b) {
if (a.l == b.l) return a.c < b.c;
return a.l < b.l;
}
signed main() {
cin >> n >> m;
for (int i = 0; i < m; i++) {
p[i] = i;
}
for (int i = 0; i < m; i++) {
cin >> e[i].x >> e[i].y >> e[i].l >> e[i].c;
}
sort(e, e + m, cmp);
for (int i = 0; i < m; i++) {
s it = e[i];
int rx = find(it.x);
int ry = find(it.y);
if (rx != ry) {
p[rx] = ry;
ans += it.c;
g[it.x].push_back({it.y, it.l});
g[it.y].push_back({it.x, it.l});
} else if (dijk(it.x, it.y, it.l)) {
ans += it.c;
g[it.x].push_back({it.y, it.l});
g[it.y].push_back({it.x, it.l});
}
}
cout << ans << endl;
return 0;
}
