int main(){
	int i,k=0,m,n;
	scanf("%d",&n);
	int a[10000];
	char buf[21];
	for(m=0;m<n;m++){
		scanf("%s",buf);
	     for(i=0;buf[i];i++){  
             
            if((buf[i]=='_')||(buf[i]>='A'&&buf[i]<='Z')||(buf[i]>='a'&&buf[i]<='z')||(buf[i]>='0'&&buf[i]<='9'&&i!=0)) { 
			   a[k]=1;
			}else{
			   a[k]=0;
			   break;
			}
		}
		k++;
	}
	for(m=0;m<k;m++){
if(a[m]==0){
		   printf("no\n");
		}else{
		   printf("yes\n");
		};

	}

    return 0; 

}





