// editor1
#include <iostream>
#include <string>

using namespace std;

bool check(string s)
{
    for(char i:s)
    {
        if(!isalnum(i) && !(i == ' ' || i == ','))
        return true;
    }
    return false;
}

int main()
{
    string s;
    getline(cin, s);
    
    bool f = true;
    if(check(s))
    {
        cout << "INVALID INPUT";
        return 0;
    }
    
    if(!(s.size()>=3 && s.size()<=100))
    {
        cout << "INVALID INPUT";
        return 0;
    }
    
    string rs = "", ls = "";
    
    for(char:i:s)
    {
        if(isalpha(i))
        {
            f = false;
            break;
        }
    }
    
    if(f)
    {
        int x = stoi(s);
        
        int n = x, r = 0;
        
        while(n>0)
        {
            r  = (r*10) + (n%10);
            n/=10;
        }
        
        if(r == x)
        cout << "YES";
        else
        cout << "NO";
    }
    else
    {
        for(int i=s.size()-1;i>=0;i--)
        {
            if(s.at(i) == ' ' || s.at(i) == ',')
            continue;
            rs += tolower(s.at(i));
        }
        
        for(int i=0;i<s.size();i++)
        {
            if(s.at(i) == ' ' || s.at(i) == ',')
            continue;
            ls += tolower(s.at(i));
        }
        
        if(rs == ls)
        cout << "YES";
        else
        cout << "NO";
        
        return 0;
    }
}