#include<iostream>
#include<string>
#include<algorithm>
using namespace std;

bool isNumber(const string &s) {
    if(s.empty()) return false;
    for(char c : s)
    if(!isdigit(c)) return false;
    return true;
}

int main() {
    string input;
    getline(cin, input);
    
    if(input.find('-') != string::npos || input.find('-') != string::npos) {
        cout << "Invalid input";
        return 0;
    }
    if(isNumber(input)) {
        string rev = input;
        reverse(rev.begin(), rev.end());
        cout << (rev == input ? "YES" : "NO");
        return 0;
    }
    string cleande = "";
    for(char c : input) {
        if(isalnum(c))
        cleaned += tolower(c);
    }
    
    if(cleaned.empty()) {
        cout << "INVALID INPUT";
        return 0;
    }
    string rev = cleaned;
    reverse(rev.begin(), rev.end());
    
    cout << (rev == cleaned ? "YES" : "NO");
}