#include <bits/stdc++.h>

using namespace std;

#define setIO(s) freopen(s".in","r",stdin)

const int N=5010;

int n,cnt=1,ans=453533453,tmp;

int hd[N],to[N<<1],nex[N<<1],dis[N<<1],f[N],g[N],maxson[N],check[N<<1],val[N<<1];

inline void add(int u,int v,int c)

{

    nex[++cnt]=hd[u],hd[u]=cnt,to[cnt]=v,val[cnt]=c;

}

void dfs1(int u,int ff)

{

    for(int i=hd[u];i;i=nex[i])

    {

        int v=to[i];

        if(v==ff||check[i])   continue;

        dfs1(v,u);

        tmp=max(tmp,f[u]+f[v]+val[i]);

        if(f[v]+val[i]>f[u])   g[u]=f[u],f[u]=f[v]+val[i],maxson[u]=v;

        else if(f[v]+val[i]>g[u])  g[u]=f[v]+val[i];  

    }

}

void dfs2(int x,int ff,int maxx)

{

    tmp=min(tmp,max(maxx,f[x]));

    for(int i=hd[x];i;i=nex[i])

    {

        int v=to[i];

        if(v==ff||check[i])   continue;

        if(maxson[x]==v)  dfs2(v,x,max(g[x]+val[i],maxx+val[i]));

        else dfs2(v,x,max(f[x]+val[i],maxx+val[i]));

    }

}

inline void init()

{

    memset(f,0,sizeof(f));

    memset(g,0,sizeof(g));

    memset(maxson,0,sizeof(maxson));

}

int main()

{

    // setIO("input");

    int i,j;

    scanf("%d",&n);

    for(i=1;i<n;++i)

    {

        int u,v,w;

        scanf("%d%d%d",&u,&v,&w);

        add(u,v,w),add(v,u,w);

    }

    for(i=2;i<=cnt;i+=2)

    {

        init();

        int d1,d2,d3,d4,x=to[i],y=to[i^1];

        check[i]=check[i^1]=1;

        tmp=0, dfs1(x,0), d1=tmp;

        tmp=0, dfs1(y,0), d2=tmp;

        tmp=10000000, dfs2(x,0,0), d3=tmp;

        tmp=10000000, dfs2(y,0,0), d4=tmp;

        ans=min(ans,max(max(d1,d2),d3+d4+val[i]));

        check[i]=check[i^1]=0;

    }

    printf("%d\n",ans);

    return 0;

}