#include<stdio.h>
#define N 251
 
main(){

  int A[N];
  int i,n;

  scanf("%d",&n);

  for(i=1;i<=n;i++)scanf("%d",&A[i]);

  for(i=1;i<=n;i++){
    
    if(i==1){
      printf("node %d: key = %d, ",i,A[i]);
      if(left(i)<=n)printf("left key = %d, ",A[left(i)]);
      if(right(i)<=n)printf("right key = %d, ",A[right(i)]);
    }

    else {
      printf("node %d: key = %d, parent key = %d, ",i,A[i],A[parent(i)]);
      if(left(i)<=n)printf("left key = %d, ",A[left(i)]);
      if(right(i)<=n)printf("right key = %d, ",A[right(i)]);
    }
    printf("\n");
    
  }

  return 0;
}

int parent(int i){
  return i/2;
 
}
int left(int i){
  return 2*i;
 
}
 
int right(int i){
  return 2*i+1;
 
}