#include<stdio.h>
#define MAX 100000
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;
}

