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program p1128;
var
 n,k,i,s:integer;
 a:array[1..20] of longint;

procedure judge(sum:longint);
var
 i:longint;
begin
 if sum<2 then exit;
 if sum>2 then
    for i:=2 to trunc(sqrt(sum)) do
     if sum mod i=0 then exit;
 inc(s);
end;

procedure search(st,k:integer;sum:longint);
var i:integer;
begin
 if k=0 then begin judge(sum);exit;end;
 for i:=st to n-k+1 do
  search(i+1,k-1,sum+a[i]);
end;

begin
 readln(n,k);
 for i:=1 to n do
  read(a[i]);
 s:=0;
 search(1,k,0);
 writeln(s);
end.