include[HTML_REMOVED]
include[HTML_REMOVED]
using namespace std;
string s;
int f[1010][1010];
int main()
{
cin>>s;
int n =s.size();
//区间dp问题
//从i到j之间的最长回文序列
for(int len = 1;len <= n;len)
//左右端点
for(int i = 0; i+len -1<n;i)
{
int r= i +len-1;
if(len==1)
//初始化
f[i][r]=1;
else{
f[i][r] = max(f[i+1][r],f[i][r-1]);
if(s[i]==s[r])
f[i][r] = max(f[i][r],f[i+1][r-1]+2);
}
}
cout<<n-f[0][n-1];
return 0;
}