#include <stdio.h>

#define N 1000000

int main(){

  int i,n,a[N+1];

  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((i*2) <= n){
      printf("left key = %d, ",a[i*2]);
    }

    if((i*2+1) <= n){
      printf("right key = %d, ",a[i*2+1]);
    }

    printf("\n");
  }

  return 0;
  
}

