#include<stdio.h>

#define H 251


int A[H];

int main(){
 
  int n;
  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 != 0){
      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;
}
    