#include <stdio.h>
int main()
{
  int H,k,i;
  int A[250];

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

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