#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;
}

