#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(void){
  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;
}

