#include <bits/stdc++.h>
#define N 300005
#define mod 1000000007
using namespace std;
vector<int> adj[N];
vector<int> adj2[N];
map<pair<int,int>,int> col;
set<pair<int,int>> s[N];
bool vis[N];
int pr[N];
void dfs(int v,int par){
vector<pair<int,int>> sz;
pr[v] = par;
sz.push_back({0,0});
for(auto u:adj[v]){
if(u == par)continue;
dfs(u,v);
sz.push_back({s[u].size(),u});
}
sort(sz.rbegin(),sz.rend());
swap(s[v],s[sz[0].second]);
for(int i=1;i<sz.size();i++){
for(auto u:s[sz[i].second]){
u = {min(u.first,u.second),max(u.first,u.second)};
if(s[v].count(u)){
s[v].erase(u);
}
else s[v].insert(u);
}
}
for(auto u:adj2[v]){
pair<int,int> tmp = {min(u,v),max(u,v)};
if(s[v].count(tmp)){
s[v].erase(tmp);
}
else s[v].insert(tmp);
}
/*
cout << v << endl;
for(auto u:s[v]){
cout << u.first << " " << u.second << " " ;
}
cout << endl;*/
col[{v,par}] = !!s[v].size() + 1;
}
void solve(){
int n,m;
cin >> n >> m;
vector<pair<int,int>> edge;
for(int i=1;i<n;i++){
int u,v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
edge.push_back({u,v});
}
for(int i=0;i<m;i++){
int u,v;
cin >> u >> v;
adj2[u].push_back(v);
adj2[v].push_back(u);
}
dfs(1,0);
long long ans = 1;
//cout << col[{1,0}]<<endl;
for(auto u:edge){
if(!col[u])swap(u.first,u.second);
//cout << u.first << " " << u.second << endl;
//cout << col[u] << endl;
if(col[u] == 1)ans = ans*2%mod;
else if(!vis[u.second] && col[{u.second,pr[u.second]}] == 1){
vis[u.second] = 1;
ans = ans*2%mod;
}
}
cout << ans;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
#ifdef Local
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
#endif
int t=1;
//cin>>t;
while(t--){
solve();
}
#ifdef Local
cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
#endif
}
