#include <stdio.h>

int main(){
  int n,i,a[100001];

  scanf("%d",&n);
  for(i=1;i<=n;i++){
    scanf("%d",&a[i]);
  }

  for(i=1;i<=n;i++){
    printf("node %d: key = %d, ",i,a[i]);
    if((i/2)>=1){
      printf("parent key = %d, ",a[i/2]);
    }
    if((2*i)<=n){
      printf("left key = %d, ",a[2*i]);
    }
    if((2*i+1)<=n){
      printf("right key = %d, ",a[2*i+1]);
    }
      printf("\n");
  }

  return 0;
}

