#include <iostream>
#include <algorithm>
using namespace std;
const int N = 10000;
int n, m;
struct node{
    int x, y, w;
}ege[N];
int parent[N];
int res = 0, k = 0;
int find(int x){
    if(parent[x] == x)  return x;
    return parent[x] = find(parent[x]);
}
void read(){
    cin >> n >> m;
    for(int i = 0; i <= n; i ++ )   parent[i] = i; 
    for(int i = 0; i < m; i ++ ){
        int p, u, v, w; cin >> p >> u >> v >> w;
        if(p == 1){
            int pu = find(u), pv = find(v);
            if(pu != pv)    parent[pu] = pv;
            res += w;
        }else{
            ege[k] = {u, v, w};
            k ++ ;
        }
    }
}
bool cmp(node a, node b){
    return a.w < b.w;
}
void kruskal(){
    sort(ege, ege + k, cmp);
    for(int i = 0; i < k; i ++ ){
        int px = find(ege[i].x), py = find(ege[i].y);
        if(px != py){
            res += ege[i].w;
            parent[px] = py;
        }
    }
}
int main(){
    read();
    kruskal();
    cout << res << endl;
    return 0;
}