错误编号215

var
 n,m,i,sum,mid,l,r:longint;
 a:array[0..max_n+1] of longint;
function ok(x:longint):boolean;
var
 i,j,sum:longint;
begin
 j:=1;
 for i:=1 to m do
 if j<=n then
 begin
  sum:=0;
  while (j<=n)and(sum+a[j]<=x) do
  begin
   inc(sum,a[j]); inc(j);
  end;
 end
 else exit(true);
 if j=n+1 then exit(true);
 exit(false);
end;
begin
 readln(n,m);
 for i:=1 to n do
 begin
  read(a[i]);
  inc(r,a[i]);
  if a[i]>l then l:=a[i];
 end;
 dec(r,m-1);
 while l<r do
 begin
  mid:=(l+r) div 2;
  if ok(mid) then r:=mid
  else l:=mid+1;
 end;
 writeln(l);
end.