int main(){
	int n,i=0,j=0,a[1000],c;
	char zfc[21];
	scanf("%d",&n);
  while(j<n)
  {
    scanf("%s",zfc);
    for(i=0,c=0;zfc[i]!='\0';i++){
      if((zfc[i]>='a'&&zfc[i]<='z')||(zfc[i]>='A'&&zfc[i]<='Z')||zfc[i]=='_'||(zfc[i]>='0'&&zfc[i]<='9'))
       c++;
       
	}
	if(c==i) a[j]=1;
	else a[j]=0;
	if(a[j]==1)
	{
	  if(zfc[0]>='0'&&zfc[0]<='9')
		  a[j]=0;
	}
   j++;
  }
  for(j=0;j<n;j++)
  {
  if(a[j]==0)
  printf("no\n");
  if(a[j]==1)
  printf("yes\n");
  }


return 0;
}