#include<stdio.h>
#include<stdio.h>
int main(){
  int n,i,j;
  int H[251];
  scanf("%d",&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(2*i<=n){
      printf("left key = %d, ",H[2*i]);
    }
    if(2*i+1<=n){
	printf("right key = %d, ",H[2*i+1]);
    }
    printf("\n");
  }

  return 0;
}

