var
f:array[0..500,0..500]of int64;
n,a,b,p,i:longint;
ans:int64;

function dfs(i,j:longint):int64;
var
k:longint;
begin
    if f[i,j]>0 then exit(f[i,j]);
    if j=1 then exit(1);
    dfs:=0;
    for k:=0 to i do
        dfs:=dfs+dfs(i-k,j-1);
    dfs:=dfs mod p;
    f[i,j]:=dfs;
end;

begin
    assign(input,'sumcount.in');reset(input);
    assign(output,'sumcount.out');rewrite(output);
    read(n,a,b,p);
    for i:=a to b do
        ans:=(ans+dfs(i,n)) mod p;
    writeln(ans);
    close(input);close(output);
end.