program grupuri;
  const
    fin='grupuri.in';
    fout='grupuri.out';
    nmax=100000;
  var
    a:array[1..nmax] of longint;
    i,j,l:longint;
    n,s,nr,k:int64;
    st,dr,mid,max:int64;
begin
  assign(input,fin);
    reset(input);
    readln(k,n);
    s:=0;
    for i:=1 to n do
      begin
        read(a[i]);
        inc(s,a[i]);
      end;
  close(input);
  assign(output,fout);
    rewrite(output);
    st:=1;dr:=s div k;
    max:=0;
    while (st<=dr) do
      begin
        mid:=(st+dr) shr 1;
        nr:=0;
        for i:=1 to n do
          if a[i]<=mid then
            inc(nr,a[i])
          else
            inc(nr,mid);
        if nr>=mid*k then
          begin
            st:=mid+1;
            if mid>max then
              max:=mid;
          end
        else
          dr:=mid-1;
      end;
    writeln(max);
  close(output);
end.