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

int main()
{
  char line[200];
  int all_before(char *, char, char);

  while (gets(line) != NULL)
  {
    char a, b, str[200];
    int res;
    strcpy(str, line);
    gets(line);
    a = line[0];
    b = line[2];
    res = all_before(str, a, b);
    puts(res ? "YES" : "NO");
  }

  return EXIT_SUCCESS;
}