#include <stdio.h>
#define N 250


int main(){
  int id[N];
  int i;
  int n;
 

  scanf("%d",&n);
  for(i=1; i <=n; i++){
    scanf("%d",&id[i]);
  }

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

  return 0;
}