This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
#define sp << " " << 
#define int long long
#define vi vector<int>
#define F(xxx,yyy) for (int xxx=1;xxx<=yyy;xxx++)
#define pii pair<int,int>
#define pb push_back
const int N = 5e5+1;
const int inf = 1e9+1;
const int MOD = 1e9+7;
int mult(int x,int y) {return ((x%MOD)*(y%MOD))%MOD;}
void solve() {  
  int n,m;
  cin >> n >> m;
  vi edges[n+1];
  F(i,n-1) {
    int a,b;
    cin >> a >> b;
    edges[a].pb(b);
    edges[b].pb(a);
  }
  vi beg[n+1];
  while (m--){
    int l,r;
    cin >> l >> r;
    beg[l].pb(r);
  }
  F(i,n-1) beg[i].push_back(i+1);
  priority_queue<int,vi,greater<int>> cur_segs;
  int ans = 1;
  F(i,n) {
    while (!cur_segs.empty() && cur_segs.top() == i) cur_segs.pop();
    if (i>1 && cur_segs.empty()) {
      ans = mult(ans,2);
    }
    for (auto it : beg[i]) cur_segs.push(it);
  }
  cout << ans << endl;
} 
    
                  
                             
signed main() { 
  ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
  #ifdef Local
  freopen("in","r",stdin);
  freopen("out","w",stdout); 
  #endif
  int t = 1;
  //cin >> t;
	F(i,t) solve();
}
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