import sys
input = sys.stdin.readline

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

AINV=[0]*(N+1)
for i in range(N):
    AINV[A[i]]=i

USE=[0]*(N+1)
ANS=0

for i in range(1,N+1):
    if USE[AINV[i]]==1:
        continue
    ANS+=1
    USE[AINV[i]]=1
    USE[AINV[i]-1]=1

print(ANS)