Program expense;

Type
sc=array [1..100000] of longint;

Var
s:sc;
i,j,k,p:longint;
n,m:longint;
max,h:longint;
z,temp:longint;

Begin
assign(input,'expense.in');
assign(output,'expense.out');
reset(input);
rewrite(output);
readln(n,m);
max:=0;
h:=0;
for i:=1 to n do begin
 readln(s[i]);
 if s[i]>max then max:=s[i];
 h:=h+s[i];
end;
i:=max;
j:=h;
while i<j do begin
 k:=(i+j) div 2;
 z:=0;
 temp:=0;
 for p:=1 to n do begin
  temp:=temp+s[p];
  if temp>k then begin
   temp:=s[p];
   z:=z+1;
  end;
 end;
 if z<m then j:=k
 else i:=k+1;
end;
writeln(j);
close(input);
close(output);
End.