#include<stdio.h>
#define MAX 1000000
 
int main(){
   
  int h;
  int 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 ( i*2 <= h ) printf("left key = %d, ", A[i*2]);
    if ( i*2+1 <= h ) printf("right key = %d, ", A[i*2+1]);
 
    printf("\n");
  }
   
  return 0;
}