program DPP_AGAIN;
var  mass,stack:array[1..10001] of char;
     kol,ls,i:integer;
     res,comment,cont:boolean;
function arithm:boolean;
begin
if ((ord(mass[i])>=48) and (ord(mass[i])<=57))or(mass[i]='/')or (mass
[i]='*')or(mass[i]='+') or (mass[i]='-')or (mass[i]='(') or (mass[i]
='=') then
        arithm:=true else
        arithm:=false;
end;
begin
{     assign(input,'input.txt');
     reset(input);
     assign(output,'output.txt');
     rewrite(output);}
     fillchar(mass,sizeof(mass),#0);
     fillchar(stack,sizeof(stack),#0);
     kol:=0;
     ls:=0;
     res:=true;
     while not eof do
     begin
          while not eoln do
          begin
               inc(kol);
               read(mass[kol]);
          end;
          readln;
     end;
i:=1;
while i<=kol do
   begin
     if mass[i]='(' then
       begin
          {if begin of comment}
          if mass[i+1]='*' then
           begin
               i:=i+2;
 while (not ((mass[i]='*') and (mass[i+1]=')'))) and (i<=kol) do
        inc(i);
             if i>=kol+1 then
                  res:=false else
           inc(i);
         end else
       {if begin of arithmetic expression}
          begin
            comment:=false;
             inc(i);
              stack[1]:='(';
                    ls:=1;
            cont:=true;
            while cont do
               begin
                 if (mass[i]='(') and (mass[i+1]='*') then
                         begin
                              comment:=true;
                              inc(i);
              end;
                         if not comment then
                         begin
                              if mass[i]='(' then
                              begin
                                   inc(ls);
                                   stack[ls]:='(';
                              end;
                              if (mass[i]=')') then
                              begin
                                 if stack[ls]='(' then
                                   dec(ls) else
                                  res:=false;
                              end else
                              if not arithm then
                                 res:=false;
                         end;
                         if (mass[i]=')') and (mass[i-1]='*') then
                           comment:=false;
                         if (i>=kol) then
                           if (comment) or (ls>0) then
                              res:=false;
                         if (ls=0) or (i>=kol) then
                           cont:=false else
                           inc(i);
                    end;
               end;
          end else
          if mass[i]=')' then
            res:=false;
          if not res then
            i:=kol;
     end;
     if res then
       writeln('YES') else
       writeln('NO');
end.