#include<stdio.h>
#include<math.h>

 
int main(){
  int n,i,A[250];
 
  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;
}

