Alg/1/3

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#include <map>
#define pii pair <int, int>
#define pb(x) push_back(x)
using namespace std;
using ll = long long;
using ld = long double;
using db = double;
void cv(vector <int> &v) {
    for (auto x : v) cout << x << ' ';
    cout << "\n";
}

void cvl(vector <ll> &v) {
    for (auto x : v) cout << x << ' ';
    cout << "\n";
}


void cvv(vector <vector <int> > &v) {
    for (auto x : v) cv(x);
    cout << "\n";
}

void cvb(vector <bool> v) {
    for (bool x : v) cout << x << ' ';
    cout << "\n";
}

void cvs(vector <string>  v) {
    for (auto a : v) {
        cout << a << "\n";
    }
}

void cvp(vector <pii> a) {
    for (auto p : a) {
        cout << p.first << ' ' << p.second << "\n";
    }
    cout << "\n";
}



int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    string s; cin >> s;
    int n = s.size();
    vector <int> a(n);
    for (int i = 0; i < n; ++i) {
        a[i] = s[i] - '0';
    }
    //cv(a);
    map <int, int> cnt;
    for (int i = 0; i < n; ++i) {
        cout << s[i] << s[i] - '0' << "\n";
        if (cnt.find(a[i]) == cnt.end()) {
            //cout << "create\n";
            cnt[a[i]] == 0;
            cnt[a[i]]++;
        } else {
            //cout << "add\n";
            cnt[a[i]]++;
        }
        //cout << cnt[a[i]] << "\n";
    }
    /*cout << "cnt\n";
    for (auto p:cnt) {
        cout << p.first << ' ' << p.second << "\n";
    }
    cout << "\n";*/
    vector <int> clear;
    for (int i = 0; i < n; ++i) {
        if (cnt[a[i]] > 1) {
            clear.push_back(a[i]);
        }
    }
    //cout << "clear\n";
    //cv(clear);
    if(clear.size() % 2 == 1) {
        cout << "YES\n";
        exit(0);
    }
    bool pol = 1;
    for (int i = 0; i < clear.size() / 2; ++i) {
        if (clear[i] != clear[n - 1 - i]) {
            pol = 0;
            break;
        }
    }
    if (pol) {
        cout << "NO\n";
    } else{
        cout << "YES\n";
    }
}
//XYBAXB