1 #include<iostream>
2 #include<stdio.h>
3 #include<math.h>
4 #include<stdlib.h>
5 #include<string.h>
6 #include<limits>
7 using namespace std;
8
9 int main()
10 {
11 //freopen("in.txt","r",stdin);
12 int n;
13 char a[60];
14 cin>>n;
15 getchar();
16 while(n--)
17 {
18 gets(a);
19 int flag=0;
20 for(int i=0;i<strlen(a);i++)
21 {
22 if(a[i]=='_' || (a[i]>='0' && a[i]<='9') || (a[i]>='A' && a[i]<='Z') || (a[i]>='a' && a[i]<='z') )
23 {
24 if(i==0 && (a[i]>='0' && a[i]<='9'))
25 {
26 flag=1;
27 break;
28 }
29 continue;
30 }
31 else
32 {
33 flag=1;
34 break;
35 }
36 }
37 if(flag)
38 cout<<"no"<<endl;
39 else
40 cout<<"yes"<<endl;
41 }
42 return 0;
43 }