program fangchengdejie;
var
  n,i,j,a,b,p,sum:longint;
  c:array[1..100,0..100]of int64;
  jc:array[0..100]of int64;
function max(a,b:longint):longint;
begin
  if a>b then
    max:=a
  else
    max:=b
end;
function jie(k:longint):longint;
var
  l,z:longint;
begin
  z:=0;
  if n>=k then
    for l:=n-k to n-1 do
      z:=(z+c[n,l]*c[i-1,n-l-1])mod p
  else
    for l:=0 to n-1 do
      z:=(z+c[n,l]*c[i-1,n-l-1])mod p;
  exit(z)
end;
begin
  assign (input,'sumcount.in');
  reset (input);
  assign (output,'sumcount.out');
  rewrite (output);
    readln (n,a,b,p);
    c[n,0]:=1;
    jc[0]:=1;
    for i:=1 to max(n,b) do
      jc[i]:=jc[i-1]*i;
    for i:=1 to n do
      c[n,i]:=jc[n]div(jc[i]*jc[n-i]);
    c[a-1,0]:=1;
    for i:=1 to a-1 do
      c[a-1,i]:=jc[a-1]div(jc[i]*jc[a-1-i]);
    for i:=a to b do
    begin
      c[i,0]:=1;
      for j:=1 to i do
        c[i,j]:=jc[i]div(jc[j]*jc[i-j]);
      sum:=(sum+jie(i))mod p
    end;
    writeln (sum);
  close (input);
  close (output)
end.