program Project1;
{$APPTYPE CONSOLE}
uses
  SysUtils;

var inp,outp: text;
    n,i,j,c,wsp1,wsp2,ans: longint;
    a: array[1..200000,1..2]of longint;
    b: array[1..200000]of integer;
    f: boolean;
begin
   assign(inp,'task.in');
   assign(outp,'task.out');
   reset(inp);
   rewrite(outp);
   readln(inp,n);
   for i:=1 to n do
      readln(inp,a[i,1],a[i,2]);
   for i:=1 to n do
      if a[i,1]<a[i,2]then
         begin
            c:=a[i,1];
            a[i,1]:=a[i,2];
            a[i,2]:=c;
         end;
   for i:=1 to n-1 do
      for j:=i+1 to n do
         if a[j,1]<a[i,1]then
            begin
               wsp1:=a[i,1];
               a[i,1]:=a[j,1];
               a[j,1]:=wsp1;
               wsp2:=a[i,2];
               a[i,2]:=a[j,2];
               a[j,2]:=wsp2;
            end;
   ans:=0;
   for i:=1 to n-1 do
      for j:=i+1 to n do
         if (a[j,2]>=a[i,2])and(b[i]<>-1)then
            begin
               inc(ans);
               b[i]:=-1;
            end;
   writeln(outp,ans);
   close(inp);
   close(outp);
end.