#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 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;
}

