var
  n,k,i,j,max,t,tt:longint;
  opt:array[0..41,0..7]of longint;
  c:char;
  num:array[0..41]of 0..9;
function
  make(l,r:longint):longint;
  var
    i:longint;
  begin
    make:=0;
    for i:=l to r do
      make:=make*10+num[i];
  end;
begin
  readln(n,k);
  for i:=1 to n do
    begin
      read(c);
      num[i]:=ord(c)-48;
    end;
  for i:=1 to n do
    for j:=1 to i do
      opt[i,0]:=opt[i,0]*10+num[j];
  for i:=1 to n do
    for j:=1 to k do
      begin
        max:=0;
        for t:=j to i-1 do
          begin
            tt:=opt[t,j-1]*make(t+1,i);
            if max<tt then max:=tt;
          end;
        opt[i,j]:=max;
      end;
  writeln(opt[n,k]);
end.