#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 i,n,A[MAX+1];
    
  scanf("%d",&n);
  for(i=1;i<=n;i++)
    scanf("%d",&A[i]);
    
  for(i=1;i<=n;i++){
    printf("node %d: key = %d, ",i,A[i]);
    if(parent(i) >= 1)printf("parent key = %d, ",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;
}
   