N,K = map(int,input().split())
e = [[] for _ in range(N)]
edge = dict()
I = 0
for _ in range(N-1):
    a,b,c = map(int,input().split())
    a -= 1
    b -= 1
    e[a].append(b)
    e[b].append(a)
    edge[(a,b)]=c
    edge[(b,a)]=c
    
depth = [-1]*N
leaves = [-1]*N
depth[0] = 0
for i in range(1,N):
    if len(e[i])==1:
        leaves[i] = 1
def dfs(x):
    
    if leaves[x] !=-1:
        return leaves[x]
    
    tmp = 0
    for ix in e[x]:
        if depth[ix]==-1:
            depth[ix] = depth[x]+1
    
    for ix in e[x]:
        if depth[ix]>depth[x]:
            tmp += dfs(ix)
            
    leaves[x] = tmp
    return tmp
    
dfs(0)
E = []

for i in range(N):
    
    for j in e[i]:
        
        if depth[j]<depth[i]:
            c = edge[(i,j)]
            E.append((c,c*leaves[i]))
            I += c*leaves[i]
            break

N = len(E)
dp = [[0]*(K+2) for _ in range(N)]
a,b = E[0]
dp[0][min(a,K+1)]=b
for i in range(N-1):
    a,b = E[i+1]
    for j in range(K+1):
        
        dp[i+1][min(j+a,K+1)] = max(dp[i][j] + b,dp[i][min(j+a,K+1)])

print(max(dp[-1][:K+1])+I)