#include<stdio.h>

int main()
{

  int i, h;
  int A[250];

  scanf("%d", &h);

  for(i = 1; i <= h; i++){
    scanf("%d", &A[i]);
  }

  //parent:i/2, left:2*i, right:2*i+1

  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(2*i <= h) printf("left key = %d, ", A[2*i]);
    if(2*i+1 <= h) printf("right key = %d, ", A[2*i+1]);
    printf("\n");
  }

  return 0;
}