#include <cstdio>

#include <cstring>

#include <cmath>

#include <string>

#include <iostream>

#include <algorithm>

using namespace std;

#define rep(i, n) for(int i=0; i<(n); ++i)

#define for1(i,a,n) for(int i=(a);i<=(n);++i)

#define for2(i,a,n) for(int i=(a);i<(n);++i)

#define for3(i,a,n) for(int i=(a);i>=(n);--i)

#define for4(i,a,n) for(int i=(a);i>(n);--i)

#define CC(i,a) memset(i,a,sizeof(i))

#define max(a,b) ((a)>(b)?(a):(b))

#define min(a,b) ((a)<(b)?(a):(b))

#define read(a) a=getnum()

#define print(a) printf("%d", a)

inline int getnum() { int ret=0; char c; int k=1; for(c=getchar(); c<'0' || c>'9'; c=getchar()) if(c=='-') k=-1; for(; c>='0' && c<='9'; c=getchar()) ret=ret*10+c-'0'; return k*ret; }

struct edge {

	int u, v, w;

	bool operator < (const edge &a) const { return w<a.w; }

}e[10005];

int cnt, f[2005];

int ifind(const int &x) { return x==f[x]?x:f[x]=ifind(f[x]); }

int main() {

	int n, m;

	read(n); read(m);

	for1(i, 1, n) f[i]=i;

	int u, v, w, fu, fv, p, ans=0;

	for1(i, 1, m) {

		read(p); read(u); read(v); read(w);

		if(p==1) {

			ans+=w;

			f[ifind(u)]=ifind(v);

		}

		else e[cnt].u=u, e[cnt].v=v, e[cnt++].w=w;

	}

	sort(e, e+cnt);

	for1(i, 0, cnt) {

		fu=ifind(e[i].u); fv=ifind(e[i].v);

		if(fu!=fv) {

			f[fu]=fv;

			ans+=e[i].w;

		}

	}

	print(ans);

	return 0;

}