N = int(input());
a = [int(i) for i in input().split()]
maxIndex = a.index(N)
j = 0
while maxIndex - j >= 0 and a[maxIndex - j] == N - j:
	j+=1
k = max(maxIndex - j - 1 ,0)
ans = (N - maxIndex - 1) + k
print (ans)