var
s,q:string;
i,w,j:integer;
m:int64;
begin
assign(input,'input.txt');reset(input);
assign(output,'output.txt');rewrite(output);
read(s);
for i:=1 to length(s) do
begin
 if(ord(s[i])>47)and(ord(s[i])<58) then
 begin
  if s[i]<'6' then
        if (ord(s[i+1])>47)and(ord(s[i+1])<58) then w:=1;
  if s[i]>'5' then w:=1;
 end;
 end;
if w=1 then write('NO') else write('YES');
close(input);
close(output);
end.