#include <stdio.h>
#define MAX 251

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

