#include <bits/stdc++.h>

using namespace std;

typedef long long int ll;
typedef long double ld;

typedef pair<ll, ll> ii;
typedef vector<ll> vi;
typedef vector<ii> vii;

#define PB push_back

#define FOR(prom,a,b) for( ll prom = (a); prom < (ll)(b); ++prom )
#define F(a) FOR(i,0,a)
#define FF(a) FOR(j,0,a)

#define EPS (1e-10)
#define INF ((1LL<<62LL)-1LL)

#define EQ(a,b) (fabs(a-b)/fabs(a+b) < EPS)

vi p;
vector<vi> g;
ll pare(ll id, ll par){
	p[id]=par;
	for(ll n:g[id])if(n!=par){
		pare(n,id);
	}
}
#define MAX 207
ll d[MAX][MAX][3];//no chip, chip ok, chip nok
void dp(ll id, ll par){
	F(MAX)FF(3)d[id][i][j]=0;
	d[id][0][0]=1;
	d[id][1][1]=1;
	d[id][1][2]=1;
	ll res[MAX];
	for(ll n:g[id])if(n!=par){
		dp(n,id);
		ll ne[MAX];
		F(MAX)res[i]=0;
		F(MAX)ne[i]=d[n][i][0]+d[n][i][1]; // no chip now, all ok children
		F(MAX)FF(MAX) if(i+j<MAX)res[i+j]+=d[id][i][0]*ne[j];
		F(MAX)d[id][i][0]=res[i];
		
		F(MAX)res[i]=0;
		F(MAX)ne[i]=d[n][i][0]+d[n][i][1]+d[n][i][2]; // chip now, all children
		F(MAX)FF(MAX) if(i+j<MAX)res[i+j]+=d[id][i][1]*ne[j];
		F(MAX)d[id][i][1]=res[i];
		
		F(MAX)res[i]=0;
		F(MAX)ne[i]=d[n][i][0]; // chip now, all children
		F(MAX)FF(MAX) if(i+j<MAX)res[i+j]+=d[id][i][2]*ne[j];
		F(MAX)d[id][i][2]=res[i];
	}
	F(MAX)d[id][i][1]-=d[id][i][2];
}

int main ()
{
	int N, M;
	while ( cin >> N >> M ) {
		g=vector<vi>( N );
		p=vi(N);
	
		F(N-1) {
			int x, y; cin >> x >> y;
			--x; --y;
			g[x].PB(y);g[y].PB(x);
		}
		pare(0,0);
		dp(0,0);
		ll res=d[0][M][0]+d[0][M][1];
		cout<<res<<endl;
	}
	
	return 0;
}