#include<stdio.h>
#define MAX 100000

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

int main()
{
int kazu,i,A[MAX+1];
scanf("%d",&kazu);
for(i=1;i<=kazu;i++)
scanf("%d",&A[i]);
for(i=1;i<=kazu;i++)
{
  printf("node %d: key = %d, ",i,A[i]);
  if(parent(i)>=1)printf("parent key = %d, ",A[parent(i)]);
  if(left(i)<=kazu)printf("left key = %d, ",A[left(i)]);
  if(right(i)<=kazu)printf("right key = %d, ",A[right(i)]);
  printf("\n");
}
return 0;
}

