#include<stdio.h>
#include<stdlib.h>

int main(){
  int n;
  int *A;
  int i;
  
  scanf("%d",&n);

  A = (int *)malloc((n+1) * sizeof(int));

  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>1)
      printf("parent key = %d, ",A[i/2]);

    if(i*2 <= n)
      printf("left key = %d, ",A[2*i]);

    if(i*2 + 1 <= n)
      printf("right key = %d, ",A[2*i + 1]);

    printf("\n");
  }
  
  free(A);
  return 0;
}

