#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 10;
const int MOD = 1e9 + 7;
bool vis[MAXN];
vector<int> e[MAXN];
int l[MAXN], r[MAXN], size[MAXN], cnt[MAXN];
bool flag;
long long fac[MAXN], f[MAXN];
void dfs(int v){
    vis[v] = true;
    size[v] = 1;
    cnt[v] = 0;
    for(size_t i = 0; i < e[v].size(); i++){
        int u = e[v][i];
        if(vis[u]) continue;
        dfs(u);
        if(size[u] == 1) cnt[v]++;
        else{
            if(l[v] == -1) l[v] = u;
            else if(r[v] == -1) r[v] = u;
            else flag = false;
        }
        size[v] += size[u];
    }
}
void calc(int v){
    if(r[v] != -1){
        calc(l[v]);
        calc(r[v]);
        f[v] = (f[l[v]] * f[r[v]] * 2 %MOD) * fac[cnt[v]] % MOD;
    }
    else if(l[v] != -1){
        calc(l[v]);
        f[v] = f[l[v]] * fac[cnt[v]] * 2 % MOD;
    }
    else f[v] = fac[cnt[v]];
}
int main(){
    fac[0] = 1;
    for(int i = 1; i < MAXN; i++) fac[i] = fac[i-1] * i % MOD;
    int T;
    scanf("%d", &T);
    for(int tt = 1; tt <= T; tt++){
        int n;
        scanf("%d", &n);
        for(int i = 1; i <= n; i++) e[i].clear();
        for(int i = 1; i < n; i++) {
            int x, y;
            scanf("%d%d", &x, &y);
            e[x].push_back(y);
            e[y].push_back(x);
        }
        memset(l, -1, sizeof(l));
        memset(r, -1, sizeof(r));
        memset(vis, 0, sizeof(vis));
        flag = true;
        dfs(1);
        if(flag){
            calc(1);
            printf("Case #%d: %I64d\n", tt, n==1?1:f[1]*2%MOD);
        }
        else printf("Case #%d: 0\n", tt);
    }
    return 0;
}