n=int(input())
p=[tuple(map(int,input().split())) for i in range(n)]
a=0

B=1001
L=B*B

def SUM(l,r):
  r-=1
  yl=l//B
  yr=r//B
  a=0
  if yl==yr:
    a+=sum(st1[l:r+1])
  else:
    a+=sum(st1[l:yl*B+B])
    a+=sum(st2[yl+1:yr])
    a+=sum(st1[yr*B:r+1])
  return a

def ADD(p,x):
  st1[p]+=x
  st2[p//B]+=x
  return

st1=[0]*B*B
st2=[0]*B
for l,r in p:
  a+=SUM(0,l)
  ADD(l,1)
st1=[0]*B*B
st2=[0]*B
for l,r in p:
  a+=SUM(r,L)
  ADD(r,1)
p.sort()
st1=[0]*B*B
st2=[0]*B
for l,r in p:
  a+=SUM(r,L)
  ADD(r,1)
a-=n*(n-1)//2
a//=2
print(a)