1 #include<stdio.h>
2 char s[51];
3 int lenth(char s[])
4 {
5 int i=0;
6 while(s[i])
7 ++i;
8 return i;
9 }
10 int main()
11 {
12 int i,n;
13 while(~scanf("%d",&n))
14 {
15 getchar();
16 while(n--)
17 {
18 gets(s);
19 int len=lenth(s);
20 for(i=0; i<len; ++i)
21 {
22 if(i)
23 {
24 if(!(s[i]=='_'||(s[i]>='a'&&s[i]<='z')||(s[i]>='A'&&s[i]<='Z')||(s[i]>='0'&&s[i]<='9')))
25 break;
26 }
27 else
28 if(!( s[i]=='_' || (s[i]>='a'&&s[i]<='z') || (s[i]>='A'&&s[i]<='Z') ))
29 break;
30 }
31 if(i==len)
32 printf("yes\n");
33 else
34 printf("no\n");
35 }
36 }
37 return 0;
38 }
