#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

template<typename T>
using ordered_multiset=tree<T,null_type,less_equal<T>,rb_tree_tag,tree_order_statistics_node_update>;

#define int long long

signed main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int N,K1,K2;
	cin>>N>>K1>>K2;
	vector<vector<int>>g(N+1);
	for(int i=0;i<N-1;i++){
		int a,b;
		cin>>a>>b;
		g[a].push_back(b);
		g[b].push_back(a);
	}
	int ans=0;
	auto dfs=[&](auto self,int i,int p,int d)->ordered_multiset<int>{
		ordered_multiset<int>s;
		s.insert(d);
		for(int j:g[i]){
			if(j==p){
				continue;
			}
			auto z=self(self,j,i,d+1);
			if(s.size()<z.size()){
				swap(s,z);
			}
			for(int x:z){
				ans+=s.order_of_key(K2+d*2-x+1)-s.order_of_key(K1+d*2-x);
			}
			for(int x:z){
				s.insert(x);
			}
		}
		return s;
	};
	dfs(dfs,1,0,0);
	cout<<ans<<'\n';
	return 0;
}