#include<stdio.h>
#define M 10000

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[M+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;
}

    

