import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")

#######################################################################

N = ni()
R = [i-1 for i in na()]
i = 0
z = R[0]
ans = 1
while z < N-1:
    ans += 1
    k,i = i,z
    for j in range(k+1,i+1):
        z = max(z,R[j])
print(ans)