#include <stdio.h>

int main(){
  int i,n;

  scanf("%d",&n);
  int H[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(i*2 <= n)
      printf("left key = %d, ",H[i*2]);
    if((i*2)+1 <= n)
      printf("right key = %d, ",H[(i*2)+1]);
    printf("\n");
  }

  return 0;
}
