#include<stdio.h>
#define MAX 100000

int main() {
  int n,i;
  int 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(i / 2 >= 1)
      printf("parent key = %d, ", A[i/2]);
    if(i * 2 <= n)
      printf("left key = %d, ", A[i*2]);
    if(i * 2 + 1 <= n)
      printf("right key = %d, ", A[i*2+1]);
    printf("\n");
  }
  return 0;
}

