n = int(input())
R = [0]+list(map(int,input().split()))+[n]

ans = 0
now = 1

while now < n:
    m = 0
    nex = R[now]
    for i in range(now,nex+1):
        m = max(m,R[i])
    ans += 1
    now = nex
print(ans)