#include <stdio.h>
#define H 250

int main(){
  int l,i;
  int A[H-1];

  scanf("%d",&l);

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

  for(i=1 ; i<l+1 ; i++){
    printf("node %d: key = %d, ",i,A[i]);
    if(i/2 >= 1){
      printf("parent key = %d, ",A[i/2]);
    }
    if(2*i <= l){
      printf("left key = %d, ",A[2*i]);
    }
    if(2*i+1 <= l){
      printf("right key = %d, ",A[2*i+1]);
    }
    printf("\n");
  }
  return 0;
}

