#include<stdio.h>
#define max 250

int main(){
    int i,h[max],n;
      
    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(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;
    }
   
    