#include <stdio.h>
  
#define MAX 250

int main(){
  
  int H[MAX];
  int n;
  int i;
  
  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 > 0 ) 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;
}