1 #include<stdio.h>
 2 typedef struct{
 3     char element[50];
 4     int front,rear;
 5 }SeqQueue;
 6 void Create(SeqQueue*S)
 7 {
 8     S->front=0;
 9     S->rear=0;
10     char e;
11     e=getchar();
12     S->element[S->rear]=e;
13     e=getchar();
14     while(e!='@')
15     {
16         S->rear++; 
17         S->element[S->rear]=e;
18         e=getchar();
19     }
20 }
21 int Judge(SeqQueue*S)
22 {
23     int a=S->front,b=S->rear;
24     while(a<b)
25     {
26         if(S->element[a]!=S->element[b])return 0;
27         a++,b--;
28     }
29     return 1;
30 }
31 int main()
32 {
33     SeqQueue S;
34     Create(&S);
35     if(Judge(&S))printf("yes");
36     else printf("no");
37     return 0;
38 }