#include<stdio.h>
#define MAX 100000

int parent(int i) {return i/2;}
int left(int i) {return i*2;}
int right(int i){return i*2+1;}

int main() {
  int H,i,A[MAX+1];

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

for(i=1;i<=H;i++) {
  printf("node%d: key = %d, ", i,A[i]);
  if(parent(i) >= 1) printf("parent key = %d, ", A[parent(i)]);
  if(left(i) <= H) printf("left key = %d, ", A[left(i)]);
  if(right(i) <= H) printf("right key = %d, ", A[right(i)]);
  printf("\n");

}

return 0;
}