#include <stdio.h>
#define N 250

main(){
  int i, n, heap[N];

  scanf("%d", &n);

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