/TIVI - Truyền hình

              Uses Crt;
        Var n,i,tg,d,c,kq:longint; a,b:array[1..100000] of longint;
        Procedure hoanvi(var a,b:longint); var tg:longint; begin tg:=a; a:=b; b:=tg; end;
        Procedure Sort(l,r:longint);
        var i,j,x:longint;
        begin
            i:=l; j:=r; x:=a[(l+r) div 2];
            repeat
                while a[i]<x do inc(i); while (a[j]>x) do dec(j);
                if i<=j then begin Hoanvi(a[i],a[j]); hoanvi(b[i],b[j]); inc(i); dec(j) end;
            until i>j;
            if j>l then sort(l,j); if i<r then sort(i,r);
        end;
        Begin
            readln(n);
            for i:=1 to n do begin
                readln(a[i],b[i]);
            end; sort(1,n);
            kq:=0;
            for i:=1 to n do
            begin
                d:=i+1; c:=n;
                while d<=c do
                begin
                    tg:=(d+c) div 2;
                    if a[tg]<b[i] then d:=d+1 else c:=c-1;
                end;       //writeln(tg,' ',d);
                kq:=kq+(d-i-1);
            end;
            writeln(kq);
            readln;
        End.