import sequtils, strutils,algorithm
var
    N = stdin.readLine.parseInt
    r,R,cnt : int
    A = newSeq[array[0..1, int]](0)

for i in 1..N:
    var in1 = stdin.readLine.split.map(parseInt)
    (r, R) = (in1[0], in1[1])
    A.add([r, R])

proc cmp1(x, y : array[2, int]): int =
    system.cmp(x[0], y[0])
r = 1000000001
sort(A, cmp1)
A.reverse
for a in A:
    if a[1] <= r:
        r = a[0]
    else:
        cnt += 1
        r = max(r, a[0])

echo cnt