## https://yukicoder.me/problems/no/2796

MAX_INT = 10 ** 18


class BinaryIndexTree:
    """
    フェニック木(BinaryIndexTree)の基本的な機能を実装したクラス
    """
    def __init__(self, size):
        self.size = size
        self.array = [0] * (size + 1)
    
    def add(self, x, a):
        index = x
        while index <= self.size:
            self.array[index] += a
            index += index & (-index)
    
    def sum(self, x):
        index = x
        ans = 0
        while index > 0:
            ans += self.array[index]
            index -= index & (-index)
        return ans

    def least_upper_bound(self, value):
        if self.sum(self.size) < value:
            return -1
        elif value <= 0:
            return 0

        m = 1
        while m < self.size:
            m *= 2

        k = 0
        k_sum = 0
        while m > 0:
            k0 = k + m
            if k0 < self.size:
                if k_sum + self.array[k0] < value:
                    k_sum += self.array[k0]
                    k += m
            m //= 2
        if k < self.size:
            return k + 1
        else:
            return -1


def main():
    N = int(input())
    rR = []
    for _ in range(N):
        r, R = map(int, input().split())
        rR.append((r, R))

    rR.sort(key=lambda x : x[0], reverse=True)

    # 座標圧縮
    r_set = set()
    for r, R in rR:
        r_set.add(r)
        r_set.add(R)
    r_list = list(r_set)
    r_list.sort()
    r_map = {}
    for i, r in enumerate(r_list):
        r_map[r] = i + 1

    # BinaryIndexTree
    bit = BinaryIndexTree(len(r_list))
    for r, R in rR:
        x = bit.sum(bit.size) - bit.sum(r_map[R] - 1)
        if x == 0:
            bit.add(r_map[r], 1)
        else:
            r_ = bit.least_upper_bound(bit.sum(r_map[R] - 1) + 1)
            bit.add(r_, -1)
            bit.add(r_map[r], 1)
    
    a = bit.sum(bit.size)
    print(a - 1)




    



if __name__ == "__main__":
    main()