#include <stdio.h>

#define N 251

int main(){
  int n, i;
  int A[N];

  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]);
    if(i != n)printf("\n");
}
  printf("\n");
  return 0;
}