#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const ll N = 1e5 + 2;
ll mod =1e9 + 7;
vector < ll > adj[N];
ll P[20][N], tin[N], tout[N], timer;
ll chiglel[N], depth[N], deesh[N] = {0};
void Go(ll node, ll par, ll de) {
timer ++;
depth[node] = de;
tin[node] = timer;
P[0][node] = par;
for ( int i = 1; i <= 17; i ++) P[i][node] = P[i - 1][P[i - 1][node]];
for (ll X : adj[node]) {
if ( X == par) continue;
Go(X, node, de + 1);
}
tout[node] = timer;
}
bool is_ancestor(ll x, ll y) {
if ( tin[x] <= tin[y] && tout[y] <= tout[x]) return true;
return false;
}
ll LCA(ll x, ll y) {
if ( is_ancestor(x, y)) return x;
if ( is_ancestor(y, x)) return y;
for (int i = 17; i >= 0; i --) {
if (!is_ancestor(P[i][x], y)) x= P[i][x];
}
return P[0][x];
}
ll ataman[N];
ll Get(ll x) {
if ( x == ataman[x]) return x;
return ataman[x]= Get(ataman[x]);
}
void Unite(ll x, ll y) {
x = Get(x);
y = Get(y);
if ( x == y) return ;
if ( x > y) swap(x, y);
ataman[x] = y;
}
ll Pow(ll x, ll y) {
if ( y == 0) return 1;
if ( y == 1) return x % mod;
ll r = Pow(x, y/2);
r = r * r% mod;
if (y % 2 == 1) r = r * x % mod;
return r;
}
int main() {
ll n, m, r, x,init_x, init_y, x_iig, y, i, j, ans, t;
cin >> n >> m;
for (i = 1; i < n; i ++) {
cin >> x >> y;
adj[x].push_back(y);
adj[y].push_back(x);
}
for (i = 1; i <= n; i++) ataman[i] = i;
Go(1, 1, 1);
for (i = 1; i <= m; i ++) {
cin >> x >> y;
ll lca = LCA(x, y);
init_x = x;
init_y = y;
x_iig = -1;
while ( depth[x] > depth[lca]) {
if ( chiglel[x] == 1){
if ( x_iig == -1) x_iig = 1;
else {
if ( x_iig != 1) {
cout << 0 << endl;
return 0;
}
}
}
if ( chiglel[x] == 2){
if ( x_iig == -1) x_iig = 0;
else {
if ( x_iig != 0) {
cout << 0 << endl;
return 0;
}
}
}
x = P[0][x];
}
while ( depth[y] > depth[lca]) {
if ( chiglel[y] == 1){
if ( x_iig == -1) x_iig = 0;
else {
if ( x_iig != 0) {
cout << 0 << endl;
return 0;
}
}
y = deesh[y];
continue;
}
if ( chiglel[y] == 2){
if ( x_iig == -1) x_iig = 1;
else {
if ( x_iig != 1) {
cout << 0 << endl;
return 0;
}
}
y = deesh[y];
continue;
}
y = P[0][y];
}
if ( x_iig == -1) x_iig = 1;
ll deeshee;
if ( depth[x] >= depth[lca] && depth[x] >= depth[y]) deeshee = x;
if ( depth[y] >= depth[lca] && depth[y] >= depth[x]) deeshee= y;
if ( depth[lca] >= depth[x] && depth[lca] >= depth[y]) deeshee = lca;
x = init_x;
y = init_y;
if ( x_iig == 1) {
while ( depth[x] > depth[lca]) {
chiglel[x] = 1;
Unite(x, P[0][x]);
if ( deesh[x] == 0) {
deesh[x] = deeshee;
x = P[0][x];
}
else x = deesh[x];
}
while ( depth[y] > depth[lca]) {
chiglel[y] = 2;
Unite(y, P[0][y]);
if ( deesh[y] == 0) {
deesh[y] = deeshee;
y = P[0][y];
}
else y = deesh[y];
}
}
else {
while ( depth[x] > depth[lca]) {
chiglel[x] = 2;
Unite(x, P[0][x]);
if ( deesh[x] == 0) {
deesh[x] = deeshee;
x = P[0][x];
}
else x = deesh[x];
}
while ( depth[y] > depth[lca]) {
chiglel[y] = 1;
Unite(y, P[0][y]);
if ( deesh[y] == 0) {
deesh[y] = deeshee;
y = P[0][y];
}
else y = deesh[y];
}
}
}
map < int, int > mp;
for ( i = 1; i <= n; i ++) {
mp[Get(i)] ++;
}
ans = Pow(2, mp.size() - 1);
for ( auto R : mp) {
if ( R.second >= 2) ans = ans * 2 % mod;
}
cout << ans << endl;
}
