#include <stdio.h>
 
int main(){
    int h, i, A[250], j, pk, lk, rk;

    scanf("%d", &h);
    
    for (i = 1; i <= h; i++){
        scanf("%d", &A[i]);  
    }
 
    for (i = 1; i <= h; i++){
        printf("node %d: ",i);
        printf("key = %d, ",A[i]);
        pk = A[i/2];
        lk = A[2*i];
        rk = A[2*i+1];
   
        if(i != 1){
            printf("parent key = %d, ",pk);
        }
        if(2*i <=  h){ 
            printf("left key = %d, ",lk);
        }
        if(2*i+1 <= h){     
            printf("right key = %d, ",rk);
        }
        
        printf("\n");
    }

    return 0;
}