//Δ_1002
#include<iostream>
#include<cstdio>
#include<fstream>
#include<algorithm>
#include<vector>
#include<map>
#include<set>
#include<queue>
#include<bitset>
#include<cmath>
#include<cstring>
#include<cstdlib>
using namespace std;
typedef long long LL;
typedef double DB;
const int N = 3003;
const int M = 111111;
const int inf = 1e9;
int n,m,tot,la[N],s,t,ans,f[N],c[N],g[N];
vector<int> v[N];
int fnd(int x){
    if(f[x]==x)
        return x;
    return f[x]=fnd(f[x]);
}
struct edge{
    int pr,to,co;
}e[M];
void adde(int x,int y,int z){
    tot++;
    e[tot].pr=la[x];
    e[tot].to=y;
    e[tot].co=z;
    la[x]=tot;
}
priority_queue<pair<int,int> > Q;
void solve(){
    int i,j,o,x,y;
    while(!Q.empty()){
        Q.pop();
    }
    for(i=1;i<=n;i=i+1)
        c[i]=0,g[i]=0;
    t=fnd(1);
    Q.push(make_pair(0,t));
    while(!Q.empty()){
        o=Q.top().second;
        Q.pop();
        if(g[o])
            continue;
        g[o]=1;
        for(j=v[o].size();j--;){
            x=v[o][j];
            for(i=la[x];i;i=e[i].pr){
                y=fnd(e[i].to);
                if(!g[y]){
                    c[y]+=e[i].co;
                    Q.push(make_pair(c[y],y));
                }
            }
        }
        s=t,t=x;
    }
    for(i=1;i<=n;i=i+1)
        if(f[i]==i&&!g[i])
            ans=0;
    ans=min(ans,c[t]);
}
int main()
{
    int i,j,x,y,z;
    while(cin>>n>>m){
        tot=1;
        for(i=1;i<=n;i=i+1)
            la[i]=0;
        while(m--){
            cin>>x>>y>>z;
            adde(x,y,z),adde(y,x,z);
        }
        for(i=1;i<=n;i=i+1){
            f[i]=i;
            v[i].push_back(i);
        }
        ans=inf;
        for(i=1;i<n;i=i+1){
            solve();
            if(!ans)
                break;
            s=fnd(s),t=fnd(t);
            f[s]=t;
            for(j=v[s].size();j--;)
                v[t].push_back(v[s][j]);
        }
        cout<<ans<<endl;
        for(i=1;i<=n;i=i+1)
            v[i].clear();
    }
    return 0;
}