var
  n,l,p,i,total:longint;
  ch:char;
  s:array[0..3000000]of char;
  a:array['A'..'z']of boolean;
  f,b:array['A'..'z']of longint;

function yes(k:longint):boolean;
var
  j:longint;
  c:char;
begin
  for c:='A' to 'z' do f[c]:=b[c];
  for j:=k to k+n-1 do
  begin
    f[s[j]]:=f[s[j]]-1;
    if (not a[s[j]])or(f[s[j]]<0) then exit(false)
  end;
  exit(true);
end;

begin
  assign(input,'writing.in'); reset(input);
  assign(output,'writing.out'); rewrite(output);
  readln(n,p);
  for i:=1 to n do
  begin
    read(ch);
    a[ch]:=true;
    b[ch]:=1;
  end;
  readln;
  for i:=1 to p do
  read(s[i]);
  readln;
  for i:=1 to p-n+1 do
    if yes(i) then inc(total);
  writeln(total);
  close(input);
  close(output);
end.