ll@q,l=0,w=0,d=0,s[9d5],a[],c;rep(q){ll@t;if(t&1){char@c;s[l++]=c;d?++d:c&1?w&&a[w-1]?--w:++d:c&4?w&&!a[w-1]?a[w-1]=1:++d:a[w++]=0;}else{c=s[--l];d?--d:c&1?a[w++]=1:c&4?a[w-1]=0:--w;}wt(d|w?"No":"Yes");}