var k,i,ans:longint;
    s:ansistring;
function check(l,r:longint):boolean;
var th:ansistring;
    i:longint;
begin
 th:='';
 for i:=l to r do th:=th+s[i];
// writeln(th);
 for i:=1 to length(th)div 2+1 do
  if th[i]<>th[length(th)-i+1] then exit(false);
 exit(true);
end;
begin
 readln(k);
 readln(s);
 for i:=1 to length(s) do begin
  if i+k-1>length(s) then break;
  if check(i,i+k-1) then inc(ans);
 end;
 writeln(ans);
close(input);
close(output);
end.