#include <stdio.h>#include <string.h>#include <stdlib.h>const int INF = 10000000;const int N = 160;int n,p,root;int head[N],son[N],dp[N][N];bool f[N];int min(int a, int b) {return a < b ? a : b;}void dfs(int v){ int i,j,k; for(i = 0; i <= p; i++) dp[v][i] = INF; dp[v][1] = 0; int s = son[v]; while(s) { dfs(s); for(i = p; i >= 0; i--) { int tmp = dp[v][i]+1; for(j = 1; j < i; j++) tmp = min(tmp, dp[v][j]+dp[s][i-j]); dp[v][i] = tmp; } s = head[s]; }}int main(){ int i,j,k; while(~scanf("%d%d", &n, &p)) { memset(son, 0, sizeof(son)); memset(f, 1, sizeof(f)); for(i = 1; i < n; i++) { scanf("%d%d", &j, &k); head[k] = son[j]; son[j] = k; f[k] = 0; } for(i = 1; i <= n; i++) if(f[i]) {root = i;break;} dfs(root); int ans = dp[root][p]; for(i = 1; i <= n; i++) ans = min(ans, dp[i][p]+1); printf("%dn", ans); } return 0;}
