#include <stdio.h>

int main(){
  int h,i;
  int A[250];
  
  scanf("%d",&h);
  for(i=1;i<=h;i++){
    scanf("%d",&A[i]);
  }

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

	
      

  

  

