#include <stdio.h>
#define MAX 250

int main(){
  int h, A[MAX+1], i;

  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/2>=1) printf("parent key = %d, ",A[i/2]);
    if(2*i<=h) printf("left key = %d, ",A[2*i]);
    if(2*i+1<=h) printf("right key = %d, ",A[2*i+1]);
    printf("\n");
  }

  return 0;
}
