#include<stdio.h>
#define MAX 100000
int parent(int i){return i / 2;}

int left(int i){return i * 2;}

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

int 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;
}