#include <stdio.h>

int parent(int i){
  return i/2;
}
int left(int i){
  return 2*i;
}
int right(int i){
  return 2*i+1;
}

int main(){
  int H, i, j, a[250];
  scanf("%d", &H);

  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[parent(i)]);
    }
    if(left(i)<=H){
      printf("left key = %d, ", a[left(i)]);
    }
    if(right(i)<=H){
      printf("right key = %d, ", a[right(i)]);
    }
    printf("\n");
  }

  return 0;
}

