#include<stdio.h>
#include<stdlib.h>

int main() {
	int n,i,H[250];
	
	scanf("%d",&n);
	
	for(i=1;i<=n;i++) {
		scanf("%d",&H[i]);
	}
	
	for(i=1;i<=n;i++) {
		printf("node %d: key = %d, ",i,H[i]);
		if(i!=1) printf("parent key = %d, ",H[i/2]);
		if(2*i<=n)
		printf("left key = %d, ",H[2*i]);
		if((2*i+1)<=n)
		printf("right key = %d, ",H[2*i+1]);
		printf("\n");
	}
	return 0;
}

