#include <stdio.h>
#define N 100000
int main(){
  int n, i, H, A[N];
  scanf("%d", &H);
  for( i = 1; i <= H; i++ )
    scanf("%d", &A[i]);
  for( i = 1; i <= H; i++ ){
    printf("node %d: key = %d, ", i, A[i]);
    if( i/2 >= 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;
}

