N = int(input())
lsR = list(map(lambda x:int(x)-1,input().split()))

now = 0
nextto = lsR[now]
cnt = 0
while True:
    if now == N-1:
        break
    for j in range(now,nextto):
        nextto = max(nextto,lsR[j])
    now = lsR[now]
    cnt += 1
print(cnt)