# input
import sys
input = sys.stdin.readline
II = lambda : int(input())
MI = lambda : map(int, input().split())
LI = lambda : [int(a) for a in input().split()]
SI = lambda : input().rstrip()
LLI = lambda n : [[int(a) for a in input().split()] for _ in range(n)]
LSI = lambda n : [input().rstrip() for _ in range(n)]
MI_1 = lambda : map(lambda x:int(x)-1, input().split())
LI_1 = lambda : [int(a)-1 for a in input().split()]

mod = 998244353
inf = 1001001001001001001
ordalp = lambda s : ord(s)-65 if s.isupper() else ord(s)-97
ordallalp = lambda s : ord(s)-39 if s.isupper() else ord(s)-97
yes = lambda : print("Yes")
no = lambda : print("No")
yn = lambda flag : print("Yes" if flag else "No")

prinf = lambda ans : print(ans if ans < 1000001001001001001 else -1)
alplow = "abcdefghijklmnopqrstuvwxyz"
alpup = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
alpall = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
URDL = {'U':(-1,0), 'R':(0,1), 'D':(1,0), 'L':(0,-1)}
DIR_4 = [[-1,0],[0,1],[1,0],[0,-1]]
DIR_8 = [[-1,0],[-1,1],[0,1],[1,1],[1,0],[1,-1],[0,-1],[-1,-1]]
DIR_BISHOP = [[-1,1],[1,1],[1,-1],[-1,-1]]
prime60 = [2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59]
sys.set_int_max_str_digits(0)
# sys.setrecursionlimit(10**6)
# import pypyjit
# pypyjit.set_param('max_unroll_recursion=-1')

from collections import defaultdict,deque
from heapq import heappop,heappush
from bisect import bisect_left,bisect_right
DD = defaultdict
BSL = bisect_left
BSR = bisect_right

class BIT:
    __slots__ = ["n", "data"]
    
    def __init__(self, n):
        self.n = n
        self.data = [0]*(n+1)
    
    def build(self, arr):
        for i,a in enumerate(arr):
            self.data[i+1] = a
        for i in range(1, self.n+1):
            if i + (i&-i) <= self.n:
                self.data[i + (i&-i)] += self.data[i]
    
    def add(self, p, x):
        p += 1
        while p <= self.n:
            self.data[p] += x
            p += p& -p
    
    def sum0(self, r):
        s = 0
        while r:
            s += self.data[r]
            r -= r& -r
        return s
    
    def sum(self, l, r):
        s = 0
        while r:
            s += self.data[r]
            r -= r& -r
        while l:
            s -= self.data[l]
            l -= l& -l
        return s
    
    def get(self, p):
        return self.sum0(p+1) - self.sum0(p)

    def bisect_left(self, w):
        """
        not velify
        
        if sum0(n) < w:
            n+1
        else:
            min( x | sum0(x) >= w)
        """
        if w <= 0: return 0
        x = 0
        r = 1 << self.n.bit_length()
        while r:
            if x + r <= self.n and self.data[x + r] < w:
                w -= self.data[x + r]
                x += r
            r >>= 1
        return x + 1
    
    def bisect_right(self, w):
        """
        max( x | sum0(x) <= w)
        """
        assert w >= 0
        x = 0
        r = 1 << self.n.bit_length()
        while r:
            if x + r <= self.n and self.data[x + r] <= w:
                w -= self.data[x + r]
                x += r
            r >>= 1
        return x

    def __str__(self):
        return str([self.get(i) for i in range(self.n)])

lim = 10
n = II()
bit = BIT(lim)

def solve(l, r):
    
    if r - l <= 1:
        return 0
    m = l + r >> 1
    res = solve(l, m) + solve(m, r)
    
    # print(l, r, m)
    
    le = sorted(p[l:m])
    ri = sorted(p[m:r], reverse=True)
    # print(le, ri, bit)
    
    add = []
    for l, r in ri:
        while le and le[-1][0] < l:
            nl, nr = le.pop()
            add.append(nr)
            bit.add(nr, 1)
        res += bit.sum(r+1, lim)
    # print(bit)
    for r in add:
        bit.add(r, -1)
    return res

p = []
for i in range(n):
    l, r = MI()
    p.append((l, r))

ans = solve(0, n)
print(ans)