#include<stdio.h>
#include<math.h>

int main(){
  int n;
  int i;
  
scanf("%d",&n);
 
  int A[n+1];

  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( (int)floor(i/2) != 0 ) printf("parent key = %d, ",A[((int)floor(i/2))]);
    if( 2*i <= n ) printf("left key = %d, ",A[2*i]);
    if( (2*i+1) <= n ) printf("right key = %d, ",A[(2*i+1)]);
    printf("\n");
    }      

  return 0;
}