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

int main(){
  int H,i,*A;

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

  for(i = 1;i < H + 1;i++){
    printf("node %d: key = %d, ",i,A[i]);
    if(i == 1) printf("left key = %d, right key = %d, ",A[i * 2],A[i * 2 + 1]);
    else{
      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");
  }
  
  free(A);
  return 0;
}


