#include <stdio.h>
#define N 251

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

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

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

  return 0;
}