#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<ll, ll>
#define fi first
#define sec second
#define ld long double
const int MAXN = 5e3;
const ll INF = 1e18;
const int MOD = 1e9 + 7;
const ld eps = 1e-6;
ll d[MAXN + 5];
struct DSU{
ll N;
vector<ll> par, sz;
DSU(ll _n){
N = _n;
par.resize(N + 5), sz.resize(N + 5);
for(int i = 1; i <= N; i++) par[i] = i, sz[i] = 1;
}
ll find(ll idx){
return (par[idx] == idx ? idx : par[idx] = find(par[idx]));
}
void join(ll a, ll b){
a = find(a), b = find(b);
if(a == b) return;
if(sz[a] < sz[b]) swap(a, b);
par[b] = a;
sz[a] += sz[b];
}
};
vector<pii> adj[MAXN + 5];
pii up[MAXN + 5][MAXN + 5];
ll dist[MAXN + 5];
void init(ll idx, ll par){
for(auto [i, j] : adj[idx]){
if(i != par){
dist[i] = dist[idx] + 1;
init(i, idx);
}
}
}
void dfs(ll idx, ll par, ll head){
for(auto [i, j] : adj[idx]){
if(i != par){
up[i][head] = {idx, j};
dfs(i, idx, head);
}
}
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int tc = 1;
// cin >> tc;
for(;tc--;){
ll N, M; cin >> N >> M;
for(int i = 1; i < N; i++){
d[i] = -1;
ll u, v; cin >> u >> v;
adj[u].push_back({v, i}), adj[v].push_back({u, i});
}
DSU dsu(N);
init(1, -1);
for(int i = 1; i <= N; i++){
dfs(i, -1, i);
}
bool ok = 1;
for(int i = 1; i <= M; i++){
ll a, b; cin >> a >> b;
ll tmp = b;
ll status = -1;
while(tmp != a){
if(d[up[tmp][a].sec] != -1){
if(status != -1 && d[up[tmp][a].sec] != (status ^ (dist[tmp] < dist[up[tmp][a].fi]))){
ok = 0;
break;
}
status = ((dist[tmp] < dist[up[tmp][a].fi]) != (d[up[tmp][a].sec]));
}
tmp = up[tmp][a].fi;
}
if(status == -1) status = 0;
tmp = b;
ll last = -1;
while(tmp != a){
d[up[tmp][a].sec] = (status ^ (dist[tmp] < dist[up[tmp][a].fi]));
if(last == -1) last = up[tmp][a].sec;
else dsu.join(last, up[tmp][a].sec);
tmp = up[tmp][a].fi;
}
}
if(!ok){
cout << 0 << "\n";
continue;
}
ll ans = 1;
for(int i = 1; i < N; i++){
if(dsu.find(i) == i) ans = ans * 2LL % MOD;
}
cout << ans << "\n";
}
}
/*
*/
