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

main(){
  int h, i;
  int *A;

  scanf("%d", &h);
  A = malloc(sizeof(int) * (h+1));
  for(i=1; i<=h; i++) scanf("%d", A+i);

  for(i=1; i<=h; i++){
    printf("node %d: key = %d, ", i, A[i]);
    if(i!=1) printf("parent key = %d, ", A[(i)/2]);
    if(i*2 <= h) printf("left key = %d, ", A[i*2]);
    if(i*2 < h) printf("right key = %d, ", A[i*2+1]);
    printf("\n");
  }

  free(A);
  return 0;
}