#include <stdio.h>

#define MAX 100000

int main(void){

	int H, i ,A[MAX + 1];
	
	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/2>=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;
}

