program C;
var
        f:text;
        n,i,kil,j:longint;
        mas:array[1..2,1..200000] of longint;
        flag:array[1..200000] of 0..1;
begin
        assign(f,'task.in');
        reset(f);
        readln(f,n);
        i:=1;
        while i<=n do begin
                readln(f,mas[1,i],mas[2,i]);
                flag[i]:=0;
                i:=i+1;
        end;
        close(f);
        assign(f,'task.out');
        kil:=0;
        for i:=1 to n do
                for j:=1 to n do
                        if (i<>j)and(flag[j]=0)and(flag[i]=0)and
                        (((mas[1,i]>=mas[1,j])and(mas[2,i]>=mas[2,j]))or
                        ((mas[1,i]>=mas[2,j])and(mas[2,i]>=mas[1,j]))) then
                        begin
                                kil:=kil+1;
                                flag[j]:=1;
                        end;
        writeln(kil);
        readln;
end.