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