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#include <iostream>
#include <cstdio>
#include <assert.h>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;
int n,x,y;
const int maxn=2e5+10;
const int MOD1=1e9+7;
const int base1=269;
const int MOD2=1e9+9;
const int base2=307;
char c1,c2,c3,cmid;
int tlist;
int v,t,st,b[maxn],maxdeep[maxn],dd,max_way[maxn],f1[maxn],qq,jfll[maxn],sz_sb[maxn],ans,mar[maxn],f2[maxn],m,rvh1[maxn],rvh2[maxn],sz[maxn],sbtr[maxn];
long long pw1[maxn],pw2[maxn];
vector<pair<int,int> > ed[maxn];
vector<int> nxt[maxn];
vector <pair<pair<int,int>, int> > lst[maxn];
pair<pair<int,int>, int> pr[maxn];
void dfs1(int x, int y) {
    v++;
    sbtr[x]=0;
    sz[x]=1;
    b[v]=x;
    for (int j=0;j<ed[x].size();j++) {
        int to=ed[x][j].first;
        if (to==y || mar[to]==1) continue;
        dfs1(to,x);
        sz[x]+=sz[to];
        if (sz[to]>sbtr[x]) sbtr[x]=sz[to];
    }
}
void dfs2(int x, int y, int h, int d, int hash1, int hash2) {
    if (h>0) {
        t++;
        pr[t].first=make_pair(hash1,hash2);
        pr[t].second=d;
    }
    maxdeep[d]=max(maxdeep[d],h);
    for (int j=0;j<ed[x].size();j++) {
        int to=ed[x][j].first;
        int c=ed[x][j].second;
        if (mar[to]==1 || to==y) continue;
        if (y==0) {
            d++;
            dd=d;
            maxdeep[d]=0;
        }
        dfs2(to,x,h+1,d,(1ll*hash1*base1+c)%MOD1,(1ll*hash2*base2+c)%MOD2);
    }
}
int prebuild(int x) {
    v=0;
    dfs1(x,0);
    if (v==1) return x;
    int mn=v+1;
    int rt=0;
    for (int i=1;i<=v;i++) {
        int x=b[i];
        sbtr[x]=max(sbtr[x],v-sz[x]);
        if (sbtr[x]<mn) {
            mn=sbtr[x];
            rt=x;
        }
    }
    mar[rt]=1;
    t=0;
    sz_sb[rt]=v;
    dd=0;
    dfs2(rt,0,0,0,0,0);
    int mx1=0;
    int mx2=0;
    for (int i=1;i<=dd;i++)
    if (maxdeep[i]>mx1) {
        mx2=mx1;
        mx1=maxdeep[i];
    }
    else
    if (maxdeep[i]>mx2) mx2=maxdeep[i];
    max_way[rt]=mx1+mx2;
    sort(pr+1,pr+t+1);
    int q=-1,prv=0;
    for (int i=1;i<=t;i++) {
        if (i==1 || pr[i].first!=pr[i-1].first) {
            q++;
            lst[rt].push_back(pr[i]);
            prv=pr[i].second;
            lst[rt][q].second=prv;
        }
        else
        if (prv!=pr[i].second) lst[rt][q].second=-1;
    }
    for (int i=0;i<ed[rt].size();i++) {
        int to=ed[rt][i].first;
        if (mar[to]==1) continue;
        nxt[rt].push_back(prebuild(to));
    }
    return rt;
}
int get_hash1(int l, int r) {
    if (l>r) return 0;
    return (1ll*f1[r]-1ll*f1[l-1]*pw1[r-l+1])%MOD1;
}
int get_hash2(int l, int r) {
    if (l>r) return 0;
    return (1ll*f2[r]-1ll*f2[l-1]*pw2[r-l+1])%MOD2;
}
 
bool dfs3(int x, int y, int h, int d, int hash1, int hash2) {
    if (h>m) return false;
    rvh1[x]=hash1;
    rvh2[x]=hash2;
    for (int j=0;j<ed[x].size();j++) {
        int to=ed[x][j].first;
        int c=ed[x][j].second;
        if (mar[to]==1 || to==y) continue;
        st++;
        b[st]=to;
        jfll[st]=c;
        f1[st]=(1ll*f1[st-1]*base1+c)%MOD1;
        f2[st]=(1ll*f2[st-1]*base2+c)%MOD2;
        if (h==0) d++;
        if (dfs3(to,x,h+1,d,(pw1[h]*c+hash1)%MOD1,(pw2[h]*c+hash2)%MOD2)) return true;
        st--;
    }
    int add=0;
    if (m%2==1) add=1;
    if (h>=m/2+add) {
        int len_suff=m-h;
        int pal=0;
        int len_pal=(m-len_suff*2);
        int mid=len_pal/2;
        int hashf1=rvh1[b[mid]];
        int hashf2=rvh2[b[mid]];
        int hashs1=0,hashs2=0;
        if (len_pal%2==1) mid++;
        if (mid!=0) {
            hashs1=get_hash1(mid+1,len_pal);
            if (hashs1<0) hashs1+=MOD1;
            hashs2=get_hash2(mid+1,len_pal);
            if (hashs2<0) hashs2+=MOD2;
        }
        if (hashf1==hashs1 && hashs2==hashf2) pal=1;
        if (pal==1 && h==m) return true;
        if (pal==1) {
            int hash1=get_hash1(len_pal+1,h);
            int hash2=get_hash2(len_pal+1,h);
            if (hash1<0) hash1+=MOD1;
            if (hash2<0) hash2+=MOD2;
            int l=lower_bound(lst[tlist].begin(),lst[tlist].end(),make_pair(make_pair(hash1,hash2),-2))-lst[tlist].begin();
            if (l!=lst[tlist].size() && lst[tlist][l].first==make_pair(hash1,hash2)) {
                if (lst[tlist][l].second==-1) return true;
                else
                if (lst[tlist][l].second!=d) return true;
            }
        }
    }
    return false;
}
bool go(int v) {
    mar[v]=1;
    tlist=v;
    st=0;
    if (max_way[v]>=m && dfs3(v,0,0,0,0,0)) return true;
    for (int i=0;i<nxt[v].size();i++) {
        int to=nxt[v][i];
        if (go(to)) return true;
    }
    return false;
}
int main() {
   // freopen("18.in","r",stdin);
  //  freopen("18.out","w",stdout);
    int t;
    scanf("%d",&t);
    pw1[0]=1;
    pw2[0]=1;
    for (int i=1;i<=maxn;i++) {
        pw1[i]=(pw1[i-1]*base1)%MOD1;
        pw2[i]=(pw2[i-1]*base2)%MOD2;
    }
    for (;t>=1;t--) {
        scanf("%d",&n);
        if (n==1) {
            printf("1\n");
            continue;
        }
        for (int i=1;i<=n-1;i++) {
            int x,y,z;
            scanf("%d%d%d",&x,&y,&z);
            ed[x].push_back(make_pair(y,z+1));
            ed[y].push_back(make_pair(x,z+1));
        }
        ans=1;
        int l=1;
        int r=n/2;
        int root=prebuild(1);
        while (r-l>0) {
            int mid=(r+l)/2;
            mid++;
            for (int i=1;i<=n;i++) mar[i]=0;
            m=mid*2;
            if (go(root)) l=mid;
            else r=mid-1;
        }
        m=l*2;
        for (int i=1;i<=n;i++) mar[i]=0;
        if (l*2>ans && go(root)) ans=l*2;
        l=1;
        r=n/2;
        if (n%2==0) r--;
        while (r-l>0) {
            int mid=(r+l)/2;
            mid++;
            for (int i=1;i<=n;i++) mar[i]=0;
            m=mid*2+1;
            if (go(root)) l=mid;
            else r=mid-1;
        }
        m=l*2+1;
        for (int i=1;i<=n;i++) mar[i]=0;
        if (l*2+1>ans && go(root)) ans=l*2+1;
        for (int i=1;i<=n;i++) {
            ed[i].clear();
            lst[i].clear();
            mar[i]=0;
            nxt[i].clear();
        }
        printf("%d\n",ans+1);
    }
    return 0;
}