import sys
sys.setrecursionlimit(10**6)

n,k = map(int,input().split())

ab = [[] for i in range(n)]

val = []

for i in range(n-1):
    a,b,c = map(int,input().split())
    a -= 1
    b -= 1
    ab[a].append([b,i])
    ab[b].append([a,i])
    val.append(c)

li = [0]*(n-1)

def dfs(v,pre,idx):
    tmp = 0
    for i in range(len(ab[v])):
        if ab[v][i][0] != pre:
            #print(ab[v][i]+1)
            dfs(ab[v][i][0],v,ab[v][i][1])
            tmp += li[ab[v][i][1]]
            #print(ab[v],len(ab[v]),"len")
        if i == len(ab[v])-1:
            tmp -= 1
            tmp = max(0,tmp)
        #print(v+1)
    li[idx] = tmp+1
    #print(li,idx)
    #return tmp+1
            
for v,idx in ab[0]:
    #print(v,idx)
    dfs(v,0,idx)
    #print(li,"li")

dp = [[0]*(k+1) for _ in range(n)]
ans = 0
for i in range(n-1):
    ans += val[i]*li[i]
    

for i in range(n-1):
    for j in range(k+1):
        if j-val[i] >= 0:
            dp[i+1][j] = max(dp[i][j-val[i]]+val[i]*li[i],dp[i][j])
        else:
            dp[i+1][j] = dp[i][j]
            
#for i in range(k+1):
#    add = max(add,dp[n-1][i])
#print(dp)    
add = dp[n-1][k]
print(add+ans)