#include<stdio.h>

#define H 250

int main(){
  int A[H], n, i;
  
  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 != 0)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;
}

