N = 5
V = [0,-1,1,3,1,-1]
L = [[0],[2,3,4],[1],[1],[1,5],[4]]
viz = [0]*(N+1)
SMAX = 0
def DFS(L,V,viz,currentNode):
    viz[currentNode] = 1
    global S
    S += V[currentNode]
    global SMAX
    if S > SMAX:
        SMAX = S
    for x in L[currentNode]:
        if viz[x] == 0:
            DFS(L,V,viz,x)
for i in range(1,6):
    S = 0
    DFS(L,V,viz,i)
print(SMAX)