C++ :

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<vector>
#include<queue>
#include<map>
using namespace std;
const long long N=100+5,md=1000000007;
long long n,f[N][N],g[N][N],ans;
string st;
int main()
{
	cin>>st; n=st.size();
	st=" "+st;
	for (int i=1;i<=n;i++) f[i][i]=g[i][1]=1;
	ans=n;
	for (int l=2;l<=n;l++)
	{
		for (int i=1,j=l;j<=n;i++,j++)
		{
			g[i][l]=g[i][l-1];
			if (st[i]!=st[j]) continue;
			f[i][j]=1;
			for (int k=i+1;k<=j-1;k++)
			{
				f[i][j]+=g[k][j-k];
				f[i][j]%=md;
			}
			g[i][l]+=f[i][j]; g[i][l]%=md;
			ans+=f[i][j]; ans%=md;
		}
	}
	cout<<ans;
	return 0;
}