#include<stdio.h>
#define MAX 100000

int main(){
  int H, i;
  int A[MAX+1];

  scanf("%d", &H);

  for ( i = 1; i <= H; i++ ) scanf("%d", &A[i]);

  for ( i = 1; i <= H; i++ ) {
    printf("node %d: key = %d, ", i, A[i]);

    if ( i / 2 >= 1 )
      printf("parent key = %d, ", A[i/2]);
    if ( 2*i <= H )
      printf("left key = %d, ", A[2*i]);
    if ( (2*i+1) <= H )
      printf("right key = %d, ", A[2*i+1]);

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

