program t1027;
{const fin='f:\temp\in4.txt';}
var i,j,pp,n,k:longint;
    ch:char;
    str:array[1..10000] of char;
    t,tt:boolean;
begin
{     assign(input,fin);
     reset(input);}
     j:=1;
     while not (ch=#26) do
           begin
           read(ch);
           str[j]:=ch;
           inc(j);
           end;
     n:=j-1; i:=0;
     repeat
         inc(i);
         j:=i;
         if str[i]='(' then
            if str[i+1]='*' then
               begin
                    t:=false;
                    for j:=i+2 to n do if (str[j]='*')and(str[j+1]
=')') then
                        t:=true;
                    if t=false then begin writeln('NO'); tt:=false;
halt; end
                       else i:=j+2;
                    j:=0;
               end
            else begin
                 pp:=1;
                 repeat
                       inc(j);
                       if not(str[j] in ['(',')','0'..'9','+','-
','*','/','='])
                          then begin writeln('NO'); tt:=false; halt;
end;
                       if (str[j]='*')and(str[j-1]='(') then
                          begin
                          dec(pp);
                          for k:=j+1 to n do
                              if (str[k]='*')and(str[k+1]=')') then
                                 begin j:=k+2; break; end;
                          if k>=n then begin writeln('NO');
tt:=false; halt; end;
                          end;
                       if str[j]=')' then dec(pp);
                       if pp=0 then break;
                       if str[j]='(' then inc(pp);
                 until j>=n;
                 if pp<>0 then begin writeln('NO'); tt:=false; halt;
end;
                 i:=j+1;
                 end;
     until i>=n;
     if tt then writeln('YES');
{     close(input);}
end.