#include<stdio.h>

  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 H,i,A[1000000];
  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");
  }
}

