N = int(input())
R = list(map(int, input().split()))
start, end = 0, R[0]-1
dis = 1
while end < N-1:
    dis += 1
    end2 = end
    for i in range(start+1, end+1):
        end2 = max(end2, R[i])
    end = end2
print(dis)