#include <stdio.h>

  int main() {
    int first, second, third, forth; //,output1, ;

    scanf("%d %d   %d %d", &first, &second, &third, &forth);

    if (first >= third) { //case 2,4,5,6,8
      if (second <= forth && first <= forth) { // case 2
        printf("[%d,%d]\n", first, second);
      }
      if (first < forth && second > forth) { // case 4
        printf("[%d,%d]\n", first, forth);

      }

      if (forth < first && forth < second) { // case 8
        printf("[]\n" );

      }

    }
    if (third > first) { //case 1,3,7
      if (second >= third && forth >= second) { //case 1
        printf("[%d,%d]\n", third, second );

      }
      if (second > third && second > forth) { //case 3
        printf("[%d,%d]\n",third, forth );

      }
      if (second < third && second < forth) { //case 7
        printf("[]\n");

      }

    }


    return 0;
  }