n = int(input())
p = list(map(int, input().split()))
p = list(reversed(p))
takeda = [x for x in range(1, n+1)]
ansT, ansS = 0, 0

for i in range(n):
	score = n-i
	for j in range(len(takeda)):
		if takeda[j] > p[i]:
			ansT += score
			takeda.remove(takeda[j])
			break
	else:
		if takeda == p:
			takeda = takeda[1:]
			continue
		takeda = takeda[1:]
		ansS += score
print(ansT - ansS)