#include<stdio.h>
#define MAX 100000

int main(){
  int i, n;
  int tree[MAX+1];

  scanf("%d", &n);
  for(i=1; i<=n; i++){
    scanf("%d", &tree[i]);
  }

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

  return 0;
}

