import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N,*A = map(int,read().split())

position = [0] * (N+1)
for i,x in enumerate(A):
    position[x] = i

x = 1
for n in range(N-1,0,-1):
    if position[n] < position[n+1]:
        x += 1
    else:
        break

answer = N - x
print(answer)