{ 100p !!!}
program grupuri;
const max=100000;
var a: array[1..max] of longint;
    s: array[0..max] of int64;
  i,k,n: longint;
   nr: int64;
    f: text;

procedure citire;
var i: longint;
begin
  assign(f,'grupuri.in');
  reset(f);
  readln(f,k,n);
  for i:=1 to n do
  begin
    read(f,a[i]);
    s[i]:=s[i-1]+a[i];
  end;
  close(f)
end;


begin
  citire;

  i:=n;
  while a[i]>(S[i] div k) do
  begin
     dec(i);
     dec(k);
  end;
  nr:=S[i] div k;
  assign(f,'grupuri.out');
  rewrite(f);
  writeln(f,nr);
  close(f);
end.