var g,f:text;
x,s:longint;
i,j,k,n,a,b,l:longint;
v:array[1..500000] of longint;
begin
assign(f,'divk.in');
reset(f);
readln(F,n,k,a,b);
for i:=1 to n do begin readln(f,v[i]); v[i]:=v[i] mod k; end;

close(f);
s:=0;
for i:=1 to a do
s:=s+v[i];
l:=0;

for i:=a+1 to n do
begin
x:=s;
for j:=i to i+b do
begin
x:=x+v[j];
if x mod k=0 then inc(l) else x:=x mod k;
end;
s:=(s+v[i]-v[i-a]) mod k;

end;
assign(g,'divk.out');
rewrite(g);
writeln(g,l);
close(g);
end.