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