#include<stdio.h>
#define MAX 100000

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

int main(){
  int n, i, 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;
}