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

int main()
{
  int H,A[251],i;

  scanf("%d",&H);
  if(H>250) exit(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/2 >= 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;
}


