#include <stdio.h>
#define N 250
int main() {
  int A[N];
  int count,i;

  scanf("%d",&count);
  for(i=0;i<count;i++) scanf("%d",&A[i]);
  for(i=0;i<count;i++){
    printf("node %d: key = %d,",i+1,A[i]);
    if(i != 0 && i%2 == 1)printf(" parent key = %d,",A[(i-1)/2]);
    if(i != 0 && i%2 == 0)printf(" parent key = %d,",A[(i-2)/2]);
    if(i*2+1 < count)printf(" left key = %d,",A[i*2+1]);
    if(i*2+2 < count)printf(" right key = %d,",A[i*2+2]);
    printf("\n");
  }

  return 0;
}