#include<bits/stdc++.h>
#define inf 0x3f3f3f3f3f3f3f3fll
#define debug(x) cerr<<#x<<"="<<x<<endl
using namespace std;
using ll=long long;
using ld=long double;
using pli=pair<ll,int>;
using pi=pair<int,int>;
template<typename A>
using vc=vector<A>;
using ull=unsigned long long;
inline int read()
{
	int s=0,w=1;char ch;
	while((ch=getchar())>'9'||ch<'0') if(ch=='-') w=-1;
	while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
	return s*w;
}
mt19937_64 _rand(time(0)^clock());
ull mask=_rand();
inline ull h(ull x)
{
	return (x*x+998244353)*x+998244853;
}
inline ull G(ull x)
{
	x^=mask;
	x=h((x<<32)>>32)+h(x>>32);
	x^=mask;
	return x;
}
template<const int N,const int M>
struct graph
{
	int head[N+5];
	int t[M+5];
	int x[M+5];
	int cntm;
	graph(){ cntm=1;}
	inline void clear(int n=N)
	{
		cntm=1;
		for(int i=1;i<=n;i++) head[i]=0;
	}
	inline void ad(int u,int v)
	{
		cntm++;
		t[cntm]=v;
		x[cntm]=head[u];
		head[u]=cntm;
	}
	inline void add(int u,int v)
	{
		ad(u,v);
		ad(v,u);
	}
	inline int st(int num){ return head[num];}
	inline int to(int num){ return t[num];}
	inline int nx(int num){ return x[num];}
};
graph<100000,200000>g;
int n;
ull dfs(int num,int fa)
{
	ull ans=1;
	for(int i=g.st(num);i;i=g.nx(i))
	{
		int p=g.to(i);
		if(p==fa) continue;
		ans+=G(dfs(p,num));
	}
	return ans;
}
inline ll get()
{
	for(int i=1;i<n;i++) g.add(read(),read());
	ull res=dfs(1,1);
	g.clear(n);
	return res;
}
int main()
{
	int T=read();
	while(T--)
	{
		n=read();
		if(get()!=get()) printf("No\n");
		else printf("Isomorphism\n");
	}
	return 0;
}