#include<stdio.h>

#define H 250
#define NIL -1

int A[H],n;

int main(){
  int 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>=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;
}

