var 
 a,b,s,i:longint;
 ch,e:char;
 begin
  readln(a,b);
   for i:=1 to a+b+1 do
   begin 
    if ch in ['0'..'9'] then inc(s);
    if i=a+1 then e:=ch;
    end;
    if (a+b+1-s>=1) or (e<>'-') then writeln('No')
    else writeln('Yes');
    end.