#include <stdio.h>

int main (){
  int A[251],n,i;
  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!=0)
	printf("parent key = %d, ",A[i/2]);
      if(n>=2*i)
	printf("left key = %d, ",A[i*2]);
      if(n>=2*i+1)
	printf("right key = %d, ",A[i*2+1]);
      printf("\n");
  }
  return 0;
}

