#include<stdio.h>

#define N 1000

int main(){
  int i,heap[N],n;

  for(i=0;i<N;i++) heap[i] = NULL;
  
  scanf("%d",&n);
  
  for(i=1;i<=n;i++){
    scanf("%d",&heap[i]);
  }

  for(i=1;i<=n;i++){
    printf("node %d: key = %d, ",i,heap[i]);
    if(heap[i/2] != NULL) printf("parent key = %d, ",heap[i/2]);
    if(2*i <=n && heap[i*2]!=NULL) printf("left key = %d, ",heap[2*i]);
    if(2*i+1<=n && heap[i*2]!=NULL) printf("right key = %d, ",heap[2*i+1]);
    printf("\n");
  }
  return 0;
}