CONST fi = '';
VAR  a : array[1..3000]of char;
     ap : array['A'..'z']of boolean;
     b : array[1..3000000]of char;
     queue: array[1..3000000]of char;
     dem, top, bot : longint;
     s, w : qword;
     n, m : longint;
     f : text;
 
Procedure enter;
Var i: integer;
Begin
   assign(f, fi);
   reset(f);
     readln(f, n, m);
     for i:=1 to n do
      begin
        read(f, a[i]);
        ap[a[i]]:= true;
        w:= w+ord(a[i]);
      end;
     for i:=1 to m do read(f, b[i]);
   close(f);
End;
 
Procedure solve;
Var i, j, top, bot : longint;
Begin
   top:= 1; bot:= top; dem:= 0; s:= 0;
   for i:= 1 to m do
    begin
      if ap[b[i]] then
       begin
         inc(top);
         queue[top]:= b[i];
         s:= s+ord(b[i]);
         if (top-bot=n)and(s=w)then inc(dem);
         if (top-bot>n) then
          begin
            s:=s-ord(queue[i-n]);
            if w=s then inc(dem);
            inc(bot);
          end;
       end
      else if top>1 then
           begin
             s:= 0;
             dec(top);
             bot:= top;
           end;
    end;
End;
 
Procedure print;
Begin
   writeln(dem);
End;
 
BEGIN
   enter;
   solve;
   print;
END.