#include<stdio.h>

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 heap_size,i;
  int A[254];
  scanf("%d",&heap_size);
  for(i = 1; i <= heap_size; i++){
    scanf("%d",&A[i]);
  }
  for(i = 1; i <= heap_size; i++){
    printf("node %d: key = %d, ",i,A[i]);
    if(parent(i) >= 1) printf("parent key = %d, ",A[parent(i)]);
    if(left(i) <= heap_size) printf("left key = %d, ",A[left(i)]);
    if(right(i) <= heap_size) printf("right key = %d, ",A[right(i)]);
    printf("\n");
  }
  return 0;
}