def merge(q):
    st=q[0][0]
    ed=q[0][1]
    for l,r in a:
        if r<=ed:
            pass
        if l<=ed and r>ed:
            ed=r
        if l>ed:
            array.append((l,r))
            st=l
            ed=r
if __name__=="__main__":
    n=int(input())
    a=[]
    array=[]
    for i in range(n):
        l,r=map(int,input().split())
        a.append((l,r))
    a=sorted(a)
    merge(a)
    print(len(array)+1)