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

