#include <stdio.h>
#include <stdlib.h>

int main()
{
    int a, b, c, d, e;
    scanf("%i", &a);
    b = a/1000; // first
    c = (a/100)%10; // second
    d = (a%100)/10; // third
    e = a%1000; // last
    if ((b == e) || (c == d))
        printf("YES");
    else
    printf("NO");
    return 0;
}