#include<iostream>

 #include<cstdio>

 #include<map>

 #include<algorithm>

 using namespace std;

 string l1,l;

 int len,c[],tot,f[][],ll;

 map<char,int> a;

 int main() {

     cin >> l;

     l1 = l;

     int len = l.length();

     ll = len;

     for(int i = ;i < len; i++)

         l1[--ll] = l[i];

     for(int i = ;i < len; i++)

         for(int j = ;j < len; j++)

             f[i][j] = max(f[i-][j],max(f[i][j-],f[i-][j-] + (l[i] == l1[j])));

     printf("%d",len - f[len-][len-]);

     return ;

 }