#define Troy 11/23

 #define inf 0x7fffffff

 #include <bits/stdc++.h>

 using namespace std;

 inline int read(){

     int s=,k=;char ch=getchar();

     while(ch<''|ch>'')    ch=='-'?k=-:,ch=getchar();

     while(ch>&ch<='')    s=s*+(ch^),ch=getchar();

     return s*k;

 }

 const int N=1e5+;

 typedef long long ll;

 int n;

 struct edges{

     int v,w;edges *last;

 }edge[N<<],*head[N];int cnt;

 inline void push(int u,int v,int w){

     edge[++cnt]=(edges){v,w,head[u]};head[u]=edge+cnt;

 }

 int tot,root,heavy[N],size[N],top,num,T[N<<][],nT[N<<],pre[N<<];

 ll ans,t[N<<][];

 bool vis[N];

 inline void dfs(int x,int fa){

     size[x]=,heavy[x]=;

     for(edges *i=head[x];i;i=i->last)if(!vis[i->v]&&i->v!=fa){

         dfs(i->v,x);

         heavy[x]=max(heavy[x],size[i->v]);

         size[x]+=size[i->v];

     }

     heavy[x]=max(heavy[x],tot-size[x]);

     if(top>heavy[x])

         top=heavy[x],root=x;

 }

 #define g(s) t[s+n]

 #define G(s) T[s+n]

 #define f(s) pre[s+n]

 inline void update(int x,int s,int fa){

     bool a=f(s)>;

     if(G(s)[a]!=num)

         G(s)[a]=num,g(s)[a]=;

     ++g(s)[a];

     ++f(s);

     for(edges *i=head[x];i;i=i->last)if(!vis[i->v]&&i->v!=fa)

         update(i->v,s+(i->w?:-),x);

     --f(s);

 }

 inline void calc(int x,int s,int fa){

     bool a=f(s)>;

     ++f(s);

     if(G(s)[]==num)

         ans+=g(s)[];

     if(a&&G(s)[]==num){

         ans+=g(s)[];

         if(!s&&f(s)<=)    ans-=g(s)[];

     }

     for(edges *i=head[x];i;i=i->last)if(!vis[i->v]&&i->v!=fa)

         calc(i->v,s+(i->w?-:),x);

     --f(s);

 }

 inline void solve(int x){

     top=inf;

     dfs(x,x);

     vis[x=root]=true;

     G()[]=++num;

     g()[]=;

     for(edges *i=head[x];i;i=i->last)if(!vis[i->v]){

         calc(i->v,i->w?-:,x);

         update(i->v,i->w?:-,x);

     }

     for(edges *i=head[x];i;i=i->last)if(!vis[i->v]){

         tot=size[i->v];

         solve(i->v);

     }

 }

 int main(){

     n=read();

     for(int i=,u,v,w;i^n;++i){

         u=read(),v=read(),w=read();

         push(u,v,w);

         push(v,u,w);

     }

     tot=n;

     f()=;

     solve();

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

 }