#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
int main()
{
    String word1,word2;
    cin>>word1,word2;
    word2 = word1;
    reverse(word1.begin(),word1.end());
    if(word1 == word2)
    {
        cout<<"YES";
    }
    else
    {
        cout<<"NO";
    }
    return 0;
}