Program n1;
function check(s: string): boolean;
var i:integer;
begin
check:=true;
i:=1;
while i<=length(s) do
if not(s[i] in ['0'..'7']) then
begin 
check:=false;
break;
end
else i:=i+1;
end;
var st: string;
begin
readln(st);
if check(st) then writeln('yes')
else writeln('no');
end.