#include <stdio.h>
#include <stdlib.h>

int main(){
  int n,i;
  int A[250];

  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!=1)
      printf("parent key = %d, ",A[i/2]);
    if(2*i <= n)
      printf("left key = %d, ",A[i*2]);
    if(2*i+1 <= n)
      printf("right key = %d, ",A[i*2+1]);
    printf("\n");
  }

  return 0;
}

