#include<cstdio>

#include<iostream>

#include<cstring>

#include<cmath>

#include<algorithm>

#define int long long

#define R register int

using namespace std;

inline int g() {

    R ret=,fix=;register char ch; while(!isdigit(ch=getchar())) fix=ch=='-'?-:fix;

    do ret=ret*+(ch^); while(isdigit(ch=getchar())); return ret*fix;

}

struct node{int u,v,w;bool operator <(const node & y) const { return w<y.w;}}a[];

struct edge{int v,w,nxt;}e[];

int n,m,cnt,mx,mmx,mn=0x3f3f3f3f,ans,tot;

int fir[],f[][],h[][][],fa[],d[];

bool tr[];

inline void add(int u,int v,int w) {e[++cnt].v=v,e[cnt].nxt=fir[u],e[cnt].w=w,fir[u]=cnt;}

inline void ins(int u,int v,int w) {add(u,v,w),add(v,u,w);}

inline int getf(int x) {return x==fa[x]?x:fa[x]=getf(fa[x]);}

inline void dfs(int u,int fa) {

    for(R i=fir[u];i;i=e[i].nxt) {

        R v=e[i].v; if(v==fa) continue;

        f[v][]=u,h[v][][]=e[i].w,d[v]=d[u]+;

        for(R i=;d[v]>=(<<i);++i) {

            f[v][i]=f[f[v][i-]][i-];

            h[v][i][]=max(h[v][i-][],h[f[v][i-]][i-][]);

            if(h[v][i-][]==h[f[v][i-]][i-][])

                h[v][i][]=max(h[v][i-][],h[f[v][i-]][i-][]);

            else {

                h[v][i][]=min(h[v][i-][],h[f[v][i-]][i-][]);

                h[v][i][]=max(h[v][i-][],h[v][i][]);

                h[v][i][]=max(h[v][i][],h[f[v][i-]][i-][]);

            }

        } dfs(v,u);

    }

}

inline int lca(int u,int v) {

    if(d[u]<d[v]) swap(u,v); R lim=log2(d[u])+;

    for(R j=lim;j>=;--j) if(d[f[u][j]]>=d[v]) u=f[u][j];

    if(u==v) return u;

    for(R j=lim;j>=;--j) if(f[u][j]!=f[v][j]) u=f[u][j],v=f[v][j];

    return f[u][];

}

inline void calc(int u,int fa,int w) {

    mx=,mmx=; R lim=log2(d[u]-d[fa])+;

    for(R i=lim;i>=;--i) if(d[u]-d[fa]>=(<<i)){

        if(h[u][i][]>mx) mmx=mx,mx=h[u][i][];

        mx=max(h[u][i][],mx); mmx=max(mmx,h[u][i][]),u=f[u][i];

    }

    if(mx!=w) mn=min(mn,w-mx); else mn=min(mn,w-mmx);

}

signed main() {

    n=g(),m=g();

    for(R i=;i<=n;++i) fa[i]=i;

    for(R i=;i<=m;++i) a[i].u=g(),a[i].v=g(),a[i].w=g();

    sort(a+,a+m+);

    for(R i=;i<=m&&tot<n;++i) {

        R uf=getf(a[i].u),vf=getf(a[i].v);

        if(uf==vf) continue;

        fa[uf]=vf; ans+=a[i].w; tr[i]=true;

        ins(a[i].u,a[i].v,a[i].w); ++tot;

    } dfs(,);

    for(R i=;i<=m;++i) if(!tr[i]) {

        R L=lca(a[i].u,a[i].v);

        calc(a[i].u,L,a[i].w); calc(a[i].v,L,a[i].w);

    } printf("%lld\n",ans+mn);

}