n=int(input())
a=[[int(x) for x in input().split()] for i in range(n)]
c=[]
b=[]
d=[]
e=[[0 for i in range(2)]for i in range(n)]
l=0
tam=0
lastest=-1
anst=0
for i in range(n):
  c.append(a[i][1])
  b.append(a[i][1])
b.sort()
for i in range(n):
  l=c.index(b[i])
  d.append(l)
  c[l]=-1
for i in range(n):
  tam=d[i]
  e[i]=a[tam]
for i in range(n):
  if e[i][0]>=lastest:
    anst+=1
  lastest=e[i][1]
print(anst)