1 #include <cstdio>
 2 #include <algorithm>
 3 using namespace std;
 4 
 5 char oris[110005];
 6 char news[220005];
 7 int p[220005];
 8 
 9 void pretreatment()
10 {
11     news[0] = ‘$‘;
12     news[1] = ‘#‘;
13     int i,l;
14     for(i = 0,l = 2; oris[i] != ‘\0‘; ++i,l += 2){
15         news[l] = oris[i];
16         news[l+1] = ‘#‘;
17     }
18     news[l] = ‘\0‘;
19 }
20 
21 int manacher()
22 {
23     int idx,mx = 0;
24     int ans = 0;
25     for(int i = 1; news[i] != ‘\0‘; ++i){
26         p[i] = mx>i ? min(p[(idx<<1)-i],mx-i) : 1;
27         while(news[i+p[i]] == news[i-p[i]])
28             ++p[i];
29         if(i+p[i]>mx){
30             mx = i+p[i];
31             idx = i;
32         }
33         if(p[i]>ans)
34             ans = p[i];
35     }
36     return --ans;
37 }
38 
39 int main()
40 {
41     while(~scanf("%s",oris)){
42         pretreatment();
43         printf("%d\n",manacher());
44     }
45     return 0;
46 }