#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>
typedef long long ll;
typedef long double ld;
using namespace std;
const int N = 1e3 + 5;
struct Hungarian {
    const ll INF = 1000000000000000000; ///10^18
	int n,m;
	vector<vector<ll> > a;
	vector<ll> u,v;
	vector<int> p,way;
	Hungarian(int n, int m):
	n(n),m(m),a(n+1,vector<ll>(m+1,INF-1)),u(n+1),v(m+1),p(m+1),way(m+1){}
	void set(int x, int y, ll v){a[x+1][y+1]=-v;}
	ll assign(){
		for(int i = 1; i <= n; i++){
			int j0=0;p[0]=i;
			vector<ll> minv(m+1,INF);
			vector<char> used(m+1,false);
			do {
				used[j0]=true;
				int i0=p[j0],j1;ll delta=INF;
				for(int j = 1; j <= m; j++)if(!used[j]){
					ll cur=a[i0][j]-u[i0]-v[j];
					if(cur<minv[j])minv[j]=cur,way[j]=j0;
					if(minv[j]<delta)delta=minv[j],j1=j;
				}
				for(int j = 0; j <= m; j++)
					if(used[j])u[p[j]]+=delta,v[j]-=delta;
					else minv[j]-=delta;
				j0=j1;
			} while(p[j0]);
			do {
				int j1=way[j0];p[j0]=p[j1];j0=j1;
			} while(j0);
		}
		return -v[0];
	}
    vector<int> restoreAnswer() {   ///run it after assign
        vector<int> ans (n+1);
        for (int j=1; j<=m; ++j)
            ans[p[j]] = j;
        return ans;
    }
};
int main() {
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int n, m;
    cin >> n >> m;
    Hungarian H(n, n);
    for(int i = 0;i < m;i++) {
		int u, v, w;
		cin >> u >> v >> w;
		H.set(u - 1, v - 1, w);
	}
	for(int i = 0;i < n;i++)
		H.set(i, i, 0);
	cout << fixed << setprecision(9) << -H.assign() * .05;
    return 0;
}