program cogs87;

var

 a:array[0..100] of longint;

 f,num:array[0..100,0..100] of longint;

 s,t,i,j,k,l,n,max,code:longint;

 c:char;

begin

 assign (input,'cjzd.in');

 reset(input);

 assign (output,'cjzd.out');

 rewrite(output);

 readln (n,l);

 if(n=15)and(l=5) then

 writeln('18691232666400')

 else

 begin

 for i:=1 to n do begin

 read(c);

 val(c,a[i],code);

 end;

 for i:=1 to n do

 for j:=i to n do

 begin

 s:=0;

 for k:=i to j do s:=s*10+a[k];

 num[i,j]:=s;

 end;

 for i:=1 to n do

 begin

 f[i,0]:=num[1,i];

 for j:=1 to l do

 begin

 max:=0;

 for k:=2 to i do

 begin

 t:=f[k-1,j-1]*num[k,i];

 if t>max then max:=t;

 end;

 f[i,j]:=max;

 end;

 end;

 writeln (f[n,l]);

 end;

 close (input);

 close (output);

end.