#include <stdio.h>

int H[250];
 
int main(){
  int i,n;
  
  scanf("%d",&n);

  for( i=0 ; i<n ; i++ ) 
    scanf("%d",&H[i]);
 
  for( i = 1 ; i < n+1 ; i++ ){
    
    printf("node %d: key = %d, ",i,H[i-1]);
    
    if( i / 2 > 1 )
      printf("parent key = %d, ",H[i/2-1]);
    if( i / 2 == 1 )
      printf("parent key = %d, ",H[i/2-1]);
    if( i * 2 < n+1 )
      printf("left key = %d, ",H[i*2-1]);
    if( i * 2 + 1 < n+1 )
      printf("right key = %d, ",H[i*2+1-1]);
    
    printf("\n");
 
  }
 
 
  return 0;
}