#include #define EPS 1e-9 #define INF 1070000000LL #define MOD 1000000007LL #define fir first #define foreach(it,X) for(auto it=(X).begin();it!=(X).end();it++) #define numa(x,a) for(auto x: a) #define ite iterator #define mp make_pair #define rep(i,n) rep2(i,0,n) #define rep2(i,m,n) for(int i=m;i<(n);i++) #define pb push_back #define pf push_front #define sec second #define sz(x) ((int)(x).size()) #define ALL( c ) (c).begin(), (c).end() #define gcd(a,b) __gcd(a,b) #define mem(x,n) memset(x,n,sizeof(x)) #define endl "\n" using namespace std; template void deploy(std::ostream &os, const TUPLE &tuple){} template void deploy(std::ostream &os, const TUPLE &t){ os << (POS == 0 ? "" : ", ") << get(t); deploy(os, t); } template std::ostream& operator<<(std::ostream &os, std::pair &p){ os << "(" << p.first <<", " << p.second <<")";return os; } template std::ostream& operator<<(std::ostream &os, std::vector &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; } template std::ostream& operator<<(std::ostream &os, std::set &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; } template std::ostream& operator<<(std::ostream &os, std::map &mp){ int remain = mp.size(); os << "{"; for(auto e: mp) os << "(" << e.first << " -> " << e.second << ")" << (--remain == 0 ? "}" : ", "); return os; } #define DEBUG1(var0) { std::cerr << (#var0) << "=" << (var0) << endl; } #define DEBUG2(var0, var1) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG1(var1); } #define DEBUG3(var0, var1, var2) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG2(var1,var2); } #define DEBUG4(var0, var1, var2, var3) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG3(var1,var2,var3); } using ll = long long; ll memo[2010][2010]; ll memo2[2010][2010]; vector edge[2010]; int N,K; int childs[2010]; int dfs(int now, int par = -1){ childs[now] = 1; numa(x,edge[now]){ if (x != par) { childs[now] += dfs(x,now); } } return childs[now]; } void dp_go(int now, int par = -1){ int sums = 0; numa(x, edge[now]){ if (x != par) { dp_go(x, now); for (int c = 1; c <= sums; c++) { if (memo[now][c] > 0) { for (int c2 = 1; c2 <= childs[x]; c2++) { memo[now][c + c2] += memo[x][c2]; } } } for (int c = 1; c <= childs[x]; c++) { memo[now][c] += memo[x][c]; } sums += childs[x]; } } memo[now][childs[now]] = 1; return; } int main() { cin.tie(0); ios_base::sync_with_stdio(0); cin >> N >> K; rep(i,N-1){ int x,y; cin >> x >> y; edge[x].pb(y); edge[y].pb(x); } dfs(0); dp_go(0); cout << memo[0][K] << endl; return 0; }