import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.buffer.readline())
def LI(): return list(map(int, sys.stdin.buffer.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.buffer.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def BI(): return sys.stdin.buffer.readline().rstrip()
def SI(): return sys.stdin.buffer.readline().rstrip().decode()
inf = 10 ** 16
md = 10 ** 9 + 7
# md = 998244353

n,k=LI()
to=[[] for _ in range(n)]
cc=[]
for i in range(n-1):
    u,v,c=LI()
    u,v=u-1,v-1
    to[u].append((v,c,i))
    to[v].append((u,c,i))
    cc.append(c)

leaf=[0]*n
etou=[0]*n
def dfs(u=0,pu=-1,s=0):
    if u and len(to[u])==1:
        leaf[u]=1
        return s
    res=0
    for v,c,e in to[u]:
        if v==pu:continue
        etou[e]=v
        res+=dfs(v,u,s+c)
        leaf[u]+=leaf[v]
    return res

score=dfs()
dp=[-1]*(k+1)
dp[0]=0
for e in range(n-1):
    c=cc[e]
    u=etou[e]
    for i in range(k-c,-1,-1):
        if dp[i]==-1:continue
        ni=i+c
        dp[ni]=max(dp[ni],dp[i]+c*leaf[u])

print(score+max(dp))