program task_c;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var
 n,i,k1,k2,x1,y1,l1,r1,d,min,j,ind:longint;
 ans:int64;
 stack,new_stack,x,y:array[0..500000] of longint;

 f:text;

   procedure QSort1(l,r:longint);
  var
  buf:int64;
  key,i,j:longint;
  begin
  if (l<r) then
  begin
  i:=l;
  j:=r;
  key:=x[(i+j) div 2];
  while (i<j) do
  begin
  while (x[i]<key) do inc(i);
  while (x[j]>key) do dec(j);
  if (i<=j) then
  begin
  buf:=x[i];
  x[i]:=x[j];
  x[j]:=buf;
  buf:=y[i];
  y[i]:=y[j];
  y[j]:=buf;
  inc(i);
  dec(j);
  end;
  end;
  QSort1(l,j);
  QSort1(i,r);
  end;

  end;

  procedure QSort2(l,r:longint);
  var
  buf:int64;
  key,i,j:longint;
  begin
  if (l<r) then
  begin
  i:=l;
  j:=r;
  key:=y[(i+j) div 2];
  while (i<j) do
  begin
  while (y[i]<key) do inc(i);
  while (y[j]>key) do dec(j);
  if (i<=j) then
  begin
  buf:=x[i];
  x[i]:=x[j];
  x[j]:=buf;
  buf:=y[i];
  y[i]:=y[j];
  y[j]:=buf;
  inc(i);
  dec(j);
  end;
  end;
  QSort2(l,j);
  QSort2(i,r);
  end;

  end;

  procedure bin_search(rgh,h:longint);
  var
  l,r,mid:longint;
  b:boolean;
  begin
  l:=1;
  r:=rgh;
  b:=true;
  if (y[stack[l]]<=h) then begin ind:=1; b:=false; end;
  if (y[stack[r]]>h)and(b) then begin ind:=r+1; b:=false; end;
  if (b) then
  begin
  while (l+1<r) do
  begin
  mid:=(l+r) div 2;
  if (y[stack[mid]]>h) then l:=mid else r:=mid;
  end;
  ind:=l;
  if (y[stack[r]]<=h) then ind:=r;
  end;

  end;
begin
assign(f,'task.in');
reset(f);
readln(f,n);
for i:=1 to n do
begin
readln(f,x1,y1);
if (x1>y1) then begin x[i]:=y1; y[i]:=x1;  end else begin x[i]:=x1; y[i]:=y1;  end;
end;
close(f);
QSort1(1,n);

d:=x[1];
l1:=1;
r1:=1;
for i:=2 to n do
begin
if (d=x[i]) then begin r1:=r1+1; end else
begin
QSort2(l1,r1);
d:=x[i];
l1:=i;
r1:=i;
end;
end;
QSort2(l1,r1);

//for i:=1 to n do writeln(x[i],' ',y[i]);
//readln;

ans:=0;
k1:=1;
stack[1]:=1;
stack[0]:=10000000;
min:=y[1];

for i:=2 to n do
begin
if (y[i]<min) then begin k1:=k1+1; stack[k1]:=i; min:=y[i]; continue; end;
bin_search(k1,y[i]);
ans:=ans+k1-ind+1;
k1:=ind-1;
k1:=k1+1;
min:=y[i];
stack[k1]:=i;
end;
assign(f,'task.out');
rewrite(f);
writeln(f,ans);

close(f);
  { TODO -oUser -cConsole Main : Insert code here }
end.