#include <stdio.h>

#define H 250

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 n,i,j,p,r,l;
  int A[H+1];

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

  for(i=1;i<=n;i++){
    printf("node %d: key = %d, ",i,A[i]);
    if(parent(i)>=1) printf("parent key = %d, ",A[parent(i)]);
    if(left(i)<=n)  printf("left key = %d, ",A[left(i)]);
    if(right(i)<=n) printf("right key = %d, ",A[right(i)]);
    printf("\n");
  }

  return 0;

}
