const inf=99999929899;
var n,i,j,k,l,s:longint;
    a:array[0..501] of longint;
    min:array[1..501,1..501] of qword;
    bif,bof:array[1..1 shl 16] of char;

begin
 assign(input,'podm.in');
 assign(output,'podm.out');
 reset(input);
 rewrite(output);
 settextbuf(input,bif);
 settextbuf(output,bof);

  readln(n); min[2][1]:=1;
   for i:=0 to n do
    read(a[i]);

   for i:=2 to n do
    for j:=1 to n-i+1 do
     begin
      l:=i+j-1;
      min[j][l]:=inf;
       for k:=j to l do
        if min[j][l]>min[j][k]+min[k+1][l]+min[2][1]*a[j-1]*a[k]*a[l]
         then min[j][l]:=min[j][k]+min[k+1][l]+min[2][1]*a[j-1]*a[k]*a[l];
     end;

    writeln(min[1][n]);

 close(input);
 close(output);
{Totusi este trist in lume}
end.