<Hashing> TEMPLATE

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define mp make_pair
#define pb push_back
#define pii pair <int, int>

const int MOD = 1000000007;
ll mod = 1000000007;
const ll inv = 190839696;

const ll MAX = 2005;
int p = 131;

#define read1(a) int a; scanf("%d", &a)
#define read2(a, b) int a, b; scanf("%d %d", &a, &b)
#define read3(a, b, c) int a, b, c; scanf("%d %d %d", &a, &b, &c)

#define FOR(i, a, b) for (int i=a; i<b; i++)
#define F0R(i, a) for (int i=0; i<a; i++)

#define readgi(n) F0R(i, n) { scanf("%d", &arr[i]); }
#define readgs(n) F0R(i, n) { scanf("%c", &arr[i]); }

long long prefx[MAX];
long long prefx2[MAX];
long long pows[MAX];
long long powsinv[MAX];

string S;

long long part(long long l, long long r, long long prefx[]) {
    if (l==0) { return prefx[r]; }
    int res = (((prefx[r] - prefx[l-1]) * powsinv[l])+mod)%mod;
    if (res < 0) {
        res += mod;
    }

    return res;
}

bool palindrome(long long l, long long r) {
    return part(l, r, prefx) == part(S.length()-r-1, S.length()-l-1, prefx2);
}

int main() {

    cin >> S;
    int L = S.length();

    pows[0] = 1;
    powsinv[0] = 1;

    for (int i=1; i < MAX; i++) {
        powsinv[i] = (powsinv[i-1] * inv) % mod;
        pows[i] = (pows[i-1]*p)%mod;
    }

    prefx[0] = S[0] - 'a' + 1;
    prefx2[0] = S[L-1] - 'a' + 1;

    for (int i=0; i < L; i++) {
        prefx[i] = (prefx[i-1] + pows[i] * (S[i] - 'a' + 97)) % mod;
        prefx2[i] = (prefx2[i-1] + pows[i] * (S[L-1-i] - 'a' + 97)) % mod;
    }


    return 0;
}