#include<stdio.h>
int main() {
  int H, i;
  scanf("%d", &H);
  int A[H];
  for(i = 0; i < H; i++) {
    scanf("%d", &A[i]);
  }
  for(i = 0; i < H; i++) {
    printf("node %d: key = %d, ", i+1, A[i]);
    if(i != 0) {
      if(i%2 == 0) printf("parent key = %d, ", A[(i-1)/2]);
      else printf("parent key = %d, ", A[i/2]);
    }
    if(i*2+1 < H) printf("left key = %d, ", A[i*2+1]);
    if(i*2+2 < H) printf("right key = %d, ", A[i*2+2]);
    printf("\n");
  }
  return 0;
}