program banner;
uses math;
var a,b,c,d,t,k,m,n,i,j,l1,l2:longint;
    ans:int64;
    p:boolean;
function gcd(a,b:longint):longint;
begin
 if a mod b=0 then exit(b) else exit(gcd(b,a mod b));
end;
begin
assign(input,'banner.in');
reset(input);
assign(output,'banner.out');
rewrite(output);
readln(m,n,l1,l2);
for a:=0 to m do
  for b:=0 to n do
    for c:=a to m do
      for d:=0 to n do
        if (a<>b)or(c<>d) then
          begin
            p:=true;
            i:=abs(a-c);
            j:=abs(b-d);
            if (a=c)and(abs(b-d)>1) then
              p:=false
            else
            if (b=d)and(abs(a-c)>1) then
              p:=false
            else if (a<>c)and(b<>d) then
              begin
                if gcd(max(i,j),min(i,j))<>1 then
                  p:=false;
              end;
            if p and(sqrt(i*i+j*j)>=l1)and(sqrt(i*i+j*j)<=l2) then
              inc(ans);
          end;
writeln(ans);
close(output);
end.