program Project1;

{$APPTYPE CONSOLE}

var
f:text;
n,a,b,c,h:integer;
r:array [1..20000,2]of int64;
begin
assign (f,'task.in');
reset(f);
readln(f,n);
for a:=1 to n do
readln( f,r[b,1],r[b,2]);
close(f);
c:=0;
for a:=1 to n-1 do




end.