#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long ll;
const int N=1e5+5,INF=1e9+5;
inline int read(){char c=getchar();int x=0,f=1;while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}while(c>='0'&&c<='9'){x=x*10+c-'0';c=getchar();}return x*f;
}
int n,a,b,w;
struct edge{int v,w,ne;
}e[N<<1];
int h[N],cnt;
inline void ins(int u,int v,int w){cnt++;e[cnt].v=v;e[cnt].w=w;e[cnt].ne=h[u];h[u]=cnt;cnt++;e[cnt].v=u;e[cnt].w=w;e[cnt].ne=h[v];h[v]=cnt;
}int f[N],size[N],all,vis[N],root;
void dfsRt(int u,int fa){size[u]=1;f[u]=0;for(int i=h[u];i;i=e[i].ne){int v=e[i].v;if(vis[v]||v==fa) continue;dfsRt(v,u);size[u]+=size[v];f[u]=max(f[u],size[v]);}f[u]=max(f[u],all-size[u]);if(f[u]<f[root]) root=u;
}
int mark[N<<1],Z=N,c[N<<1][2];
ll ans;
void dfsAns(int u,int fa,int now){if(now==0) ans+=c[Z][0]+c[Z][1] +(mark[Z]>=1);else{if(mark[Z+now]) ans+=c[Z-now][0]+c[Z-now][1];else ans+=c[Z-now][1];}mark[Z+now]++;for(int i=h[u];i;i=e[i].ne)if(!vis[e[i].v]&&e[i].v!=fa) dfsAns(e[i].v,u,now+e[i].w);mark[Z+now]--;
}
int st[N],top;
void dfsDee(int u,int fa,int now){c[Z+now][mark[Z+now]>=1]++;st[++top]=Z+now;mark[Z+now]++;for(int i=h[u];i;i=e[i].ne)if(!vis[e[i].v]&&e[i].v!=fa) dfsDee(e[i].v,u,now+e[i].w);mark[Z+now]--;
}
void dfsSol(int u){vis[u]=1;for(int i=h[u];i;i=e[i].ne)if(!vis[e[i].v]) dfsAns(e[i].v,u,e[i].w),dfsDee(e[i].v,u,e[i].w);while(top) c[st[top]][0]=c[st[top]][1]=0,top--;for(int i=h[u];i;i=e[i].ne) if(!vis[e[i].v]){all=size[e[i].v];root=0;dfsRt(e[i].v,0);dfsSol(root);}
}
int main(){freopen("in","r",stdin);n=read();for(int i=1;i<n;i++) a=read(),b=read(),w= read()==0?-1:1,ins(a,b,w);all=n;root=0;f[0]=INF;dfsRt(1,0);dfsSol(root);printf("%lld",ans);
}

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long ll;
const int N=1e5+5,INF=1e9+5;
inline int read(){char c=getchar();int x=0,f=1;while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}while(c>='0'&&c<='9'){x=x*10+c-'0';c=getchar();}return x*f;
}
int n,a,b,w;
struct edge{int v,w,ne;
}e[N<<1];
int h[N],cnt;
inline void ins(int u,int v,int w){cnt++;e[cnt].v=v;e[cnt].w=w;e[cnt].ne=h[u];h[u]=cnt;cnt++;e[cnt].v=u;e[cnt].w=w;e[cnt].ne=h[v];h[v]=cnt;
}int f[N],size[N],all,vis[N],root;
void dfsRt(int u,int fa){size[u]=1;f[u]=0;for(int i=h[u];i;i=e[i].ne){int v=e[i].v;if(vis[v]||v==fa) continue;dfsRt(v,u);size[u]+=size[v];f[u]=max(f[u],size[v]);}f[u]=max(f[u],all-size[u]);if(f[u]<f[root]) root=u;
}
int mark[N<<1],Z=N;
ll c[N<<1][2],d[N<<1][2];
ll ans;
int mx;
void dfsRun(int u,int fa,int now){d[Z+now][mark[Z+now]>=1]++;mx=max(mx,abs(now));mark[Z+now]++;for(int i=h[u];i;i=e[i].ne)if(!vis[e[i].v]&&e[i].v!=fa) dfsRun(e[i].v,u,now+e[i].w);mark[Z+now]--;
}
void dfsSol(int u){//printf("dfsSol %d\n",u);vis[u]=1;c[Z][0]=1;int mxmx=0;for(int i=h[u];i;i=e[i].ne)if(!vis[e[i].v]){mx=1;dfsRun(e[i].v,u,e[i].w);mxmx=max(mxmx,mx);ans+=(c[Z][0]-1)*d[Z][0];for(int j=-mx;j<=mx;j++) ans+=c[Z-j][1]*d[Z+j][1]+c[Z-j][0]*d[Z+j][1]+c[Z-j][1]*d[Z+j][0];for(int j=Z-mx;j<=Z+mx;j++){c[j][0]+=d[j][0];c[j][1]+=d[j][1];d[j][0]=d[j][1]=0;}}for(int i=Z-mxmx;i<=Z+mxmx;i++) c[i][0]=c[i][1]=0;for(int i=h[u];i;i=e[i].ne) if(!vis[e[i].v]){all=size[e[i].v];root=0;dfsRt(e[i].v,0);dfsSol(root);}
}
int main(){freopen("in","r",stdin);n=read();for(int i=1;i<n;i++) a=read(),b=read(),w= read()==0?-1:1,ins(a,b,w);all=n;root=0;f[0]=INF;dfsRt(1,0);dfsSol(root);printf("%lld",ans);
}