class Node:
    def __init__(self):
        #self.parent_Node = None
        self.child_Node = []
        self.flag = False
        self.fix = False
        self.all_child = []

    def fix_all_child(self):
        if self.fix:
            return self.all_child
        self.all_child = self.child_Node.copy()
        for node in self.child_Node:
            self.all_child.extend(node.fix_all_child())
        self.fix = True
        return self.all_child
         

class tree:
    def __init__(self, Nodes):
        self.Nodes = Nodes
    def push_edge(self,low, upper):
        self.Nodes[upper].child_Node.append(self.Nodes[low])
        #self.Nodes[low].parent_Node = self.Nodes[upper]
    
    def fix_all_child(self, Node_idx):
        self.Nodes[Node_idx].fix_all_child()

N = int(input())
A = map(int, input().split())

t = tree([Node() for i in range(N)])
for idx, a in enumerate(A):
    t.push_edge(idx + 1, a)
t.fix_all_child(0)
num = 0
for i in range(N-1, -1, -1):
    num+=sum([1 if node.flag else 0 for node in t.Nodes[i].all_child])
    t.Nodes[i].flag = True

print(num)