var f,g:text;v:array[1..500000]of longint;n,a,b,k,x,i,j,s:longint;
begin
assign(f,'divk.in');reset(f);assign(g,'divk.out');rewrite(g);
read(f,n,k,a,b);
for i:=1 to n do begin
read(f,x);
s:=(s+x)mod k;
v[i]:=s;
                 end;
s:=0;
for i:=a to b do begin
if v[i]=0 then inc(s);
for j:=i+1 to n do
if v[j]=v[j-i]then inc(s);
                  end;
write(g,s);
close(f);close(g);
end.