#include<stdio.h>

int main(){
  int i,n,A[251];

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

