#include<stdio.h>

int main(){

  int n,i,a;
  int S[100001];
  
  scanf("%d",&n);

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

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