#include "bits/stdc++.h"

using namespace std;

#define x first
#define y second
#define pb push_back
#define mp make_pair
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define sz(a) int((a).size())
#define sqr(x) ((x)*(x))
#define forn(i, n) for (int i = 0; i < int(n); i++)
#define NAME "sqrtnim"
#define FREOPEN freopen(NAME".in", "r", stdin); freopen(NAME".out", "w", stdout);
#define Freopen freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);

typedef unsigned int unt;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
typedef long double geom;

const ll MOD = 1e9 + 7;
const int INF = 2e9;
const ll INF64 = 9e18;
const ld EPS = 1e-12;
const ld PI = 3.1415926535897932384626433832795028841;
const ll MD = 925262732;
const ll T = 634521;
const int N = 100010;
const int M = 501;

int n;
string s;
bool d[N][11][11], mark[N][11][11];
int ans[N];

bool rec(int l, int x, int y, int zz = 0)
{
    int r = n - l - 1 + zz;
    if (l > r)
        return (x == y);
    if (mark[l][x][y])
        return d[l][x][y];
    bool f = 0;
    if (l == r)
    {
        for (int i = 0; i < 10; i++)
            if ((i + i + y) % 10 == int(s[l] - '0') && (i + i + y) / 10 == x)
            {
                f = 1;
            }
    }
    else
    {
        for (int i = 0; i < 10; i++)
            for (int j = 0; j < 10; j++)
                for (int u = 0; u < 10; u++)
                    if ((i + j + y) % 10 == int(s[r] - '0') && (i + j + u) % 10 == int(s[l] - '0') && (i + j + u) / 10 == x && rec(l + 1, u, (i + j + y) / 10, zz))
                    {
                        f = 1;
                    }
    }
    mark[l][x][y] = 1;
    d[l][x][y] = f;
    return f;
}

void dfs(int l, int x, int y, int zz = 0)
{
    int r = n - l - 1 + zz;
    if (l > r)
        return;
    if (l == r)
    {
        for (int i = 0; i < 10; i++)
            if ((i + i + y) % 10 == int(s[l] - '0') && (i + i + y) / 10 == x)
            {
                ans[l] = i;
                return;
            }
    }
    else
    {
        for (int i = 0; i < 10; i++)
            for (int j = 0; j < 10; j++)
                for (int u = 0; u < 10; u++)
                    if ((i + j + y) % 10 == int(s[r] - '0') && (i + j + u) % 10 == int(s[l] - '0') && (i + j + u) / 10 == x && rec(l + 1, u, (i + j + y) / 10, zz))
                    {
                        ans[l] = i;
                        dfs(l + 1, u, (i + j + y) / 10, zz);
                        ans[r] = j;
                        return;
                    }
    }
}

int main()
{
    cin >> s;
    n = sz(s);
    if (!rec(0, 0, 0))
    {
        forn(i, N)
            forn(x, 11)
                forn(y, 11)
                    mark[i][x][y] = d[i][x][y] = 0;
        if (rec(1, int(s[0] - '0'), 0, 1))
        {
            dfs(1, int(s[0] - '0'), 0, 1);
            int t = n - 1;
            while (t >= 0 && ans[t] == 0)
                t--;
            for (int i = t; i >= 1; i--)
                printf("%d", ans[i]);
            return 0;
        }
        cout << 0;
    }
    else
    {
        int t = n - 1;
        dfs(0, 0, 0);
        while (t >= 0 && ans[t] == 0)
            t--;
        for (int i = t; i >= 0; i--)
            printf("%d", ans[i]);
    }
    return 0;
}

/*




*/