#include <stdio.h>
#define M 100000

int parent (int);
int left (int);
int right (int);

int main () {
  int h, i, a[M+1];

  scanf("%d", &h);
  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(parent(i) >= 1) printf("parent key = %d, ", a[parent(i)]);
    if(left(i) <= h) printf("left key = %d, ", a[left(i)]);
    if(right(i) <= h) printf("right key = %d, ", a[right(i)]);
    printf("\n");
  }

  return 0;
}

int parent (int i) {
  return i / 2;
}

int left (int i) {
  return 2 * i;
}

int right (int i) {
  return 2 * i + 1;
}