#include<stdio.h>
#define MAX 250
int main(){
	int i,n;
	int H[MAX];
	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/2!=0) printf("parent key = %d, ",H[i/2]);
	    if(i*2<=n) printf("left key = %d, ",H[i*2]);
	    if(i*2+1<=n) printf("right key = %d, ",H[i*2+1]);
	    printf("\n");
	}
	return 0;
}
