#include <stdio.h>

#define MAX 1000

int main() {

  int A[MAX],n,i;

  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(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;

}