N = int(input())
rRs = [tuple(map(int, input().split())) for _ in range(N)]

vs = []
for r, R in rRs:
    vs.append((r, 1))
    vs.append((R, 0))

vs.sort()

ret = N - 1

sz = 0
for v, sgn in vs:
    if sgn == 0:
        sz += 1
    elif sz:
        sz -= 1
        ret -= 1

print(ret)