#include <bits/stdc++.h>
using namespace std;
typedef long long   signed int LL;
typedef long long unsigned int LU;
#define incII(i, l, r) for(int i = (l)    ; i <= (r); ++i)
#define incID(i, l, r) for(int i = (l)    ; i <  (r); ++i)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); --i)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); --i)
#define inc(i, n)  incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define dec(i, n)  decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)
#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define  ALL(v)  v.begin(),  v.end()
#define RALL(v) v.rbegin(), v.rend()
template<typename T> bool setmin  (T & a, T b) { if(b <  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmax  (T & a, T b) { if(b >  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } }
template<typename T> bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } }
LL mo(LL a, LL b) { assert(b > 0); a %= b; if(a < 0) { a += b; } return a; }
LL fl(LL a, LL b) { assert(b > 0); return (a > 0 ? a / b : (a - b + 1) / b); }
LL ce(LL a, LL b) { assert(b > 0); return (a < 0 ? a / b : (a + b - 1) / b); }
#define bit(b, i) (((b) >> (i)) & 1)
#define BC __builtin_popcountll
#define SC(T, v) static_cast<T>(v)
#define SI(v) SC(int, v.size())
#define SL(v) SC( LL, v.size())
#define RF(e, v) for(auto & e: v)
#define ei else if
#define UR assert(false)

// ---- ----

const int M = 5001;
bool f[M][M];
int dp[M], MOD = 1e9 + 7;

int main() {
	string s;
	cin >> s;
	int n = SI(s);
	int h = fl(n, 2);
	
	incII(i, 0, h) {
		f[i][i] = true;
		int j = n - i;
		inc1(k, h) {
			if(! (0 <= i - k && i + k <= h)) { break; }
			int ia = i - k;
			int ib = i + k - 1;
			int ja = j - k;
			int jb = j + k - 1;
			bool g = (s[ia] == s[ja] && s[ib] == s[jb]);
			f[i - k][i + k] = g;
			if(! g) { break; }
		}
	}
	inc(i, h) {
		int j = n - i - 1;
		f[i][i + 1] = (s[i] == s[j]);
		inc1(k, h) {
			if(! (0 <= i - k && i + k <  h)) { break; }
			int ia = i - k;
			int ib = i + k;
			int ja = j - k;
			int jb = j + k;
			bool g = (s[ia] == s[ja] && s[ib] == s[jb]);
			f[i - k][i + k + 1] = g;
			if(! g) { break; }
		}
	}
	
	int ans = 0;
	dp[0] = 1;
	incII(i, 0, h) {
		inc(j, i) { if(f[j][i]) { (dp[i] += dp[j]) %= MOD; } }
		(ans += dp[i]) %= MOD;
	}
	
	cout << ans << endl;
	
	return 0;
}