#include <stdio.h>
int H[251];

int main(){
  int i,n;
 
  scanf("%d",&n);
  for(i=0;i<n;i++) scanf("%d",&H[i]);

  for(i=1;i<n+1;i++){
    printf("node %d: key = %d, ",i,H[i-1]);
    if(i/2>=1) printf("parent key = %d, ",H[i/2-1]);
    if(i*2<n+1) printf("left key = %d, ",H[i*2-1]);
    if(i*2+1<n+1) printf("right key = %d, ",H[i*2+1-1]);
    printf("\n");

}


  return 0;
}