#include<stdio.h>
#define MAX 10000

int main(){
  int n, i;
  int A[MAX+1];
  
  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 / 2 >= 1 ){
      printf("parent key = %d, ", A[i/2]);
    }
    if ( i*2 <= n ){
      printf("left key = %d, ", A[i*2]);
    }
    if ( i*2+1 <= n ){
      printf("right key = %d, ", A[i*2+1]);
    }
    printf("\n");
  }
  
  return 0;
}

