Program grupuri;
var a:array [0..100010] of int64;
   n,i,k:longint;
   fi,fo:text;
begin
 assign(fi,'grupuri.in');
  assign(fo,'grupuri.out');
 reset(fi);
  rewrite(fo);
 readln(fi,k,n);
 for i:=1 to n do begin
                    read(fi,a[i]);
                    a[i]:=a[i]+a[i-1];
                    end;
 while a[n]-a[n-1]>trunc(a[n]/k) do begin
                                dec(n);
                                dec(k);
                                end;
 write(fo,trunc(a[n]/k));
close(fo);
end.