#include <stdio.h>

int main () {
  int n = 0;
  int a[6] = {};
  
  int res = 0;
  
  res = scanf("%d", &n);
  for (int i = 0; i < 6; i++) {
    res = scanf("%d", a+i);
  }
  
  if (n < 3 || a[0] == a[2] || a[0] == a[5] || a[1] == a[2] || a[2] == a[3] || a[2] == a[4]) {
    printf("NO\n");
  } else {
    printf("YES\n");
  }
  
  return 0;
}