#include <stdio.h>

int main()
{
  int H,i;

  scanf("%d",&H);

  int A[H+1];

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

    if(i>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;
}
