#include <stdio.h>
 
#define MAX 250
 
int h[MAX];
 
main(){
   
  int i, n;
   
  scanf("%d", &n);
   
  for(i = 1; i <= n; i++) scanf("%d", &h[i]);
       
  for(i = 1; i <= n; i++){
     
    printf("node %d: key = %d, ", i, h[i]);
     
    if(i != 1) printf("parent key = %d, ", h[i / 2]);
     
    if(2 * i <= n) printf("left key = %d, ", h[2 * i]);  
     
    if(2 * i + 1 <= n) printf("right key = %d, ", h[2*i+1]);
     
    printf("\n");
     
  }
   
  return 0;
   
}