#include<stdio.h>
#define MAX 2000000
 
int main(){
  int n;
  int i;
  int A[MAX];
 
  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;
}