#include<stdio.h>
#define MAX 100000

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

main() {
  int H, i, A[MAX+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;
}