#include<stdio.h>
#define MAX 10000

int parent(int i) { return i/2;}
int left(int i) { return 2*i;}
int right(int i){ return 2*i+1;}

int main(){
    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(parent(i) >= 1) printf("parent key = %d, ",A[parent(i)]);
        if((left(i) <= H) && (A[left(i)]!=0)) printf("left key = %d, ",A[left(i)]);
        if((right(i) <= H) && (A[right(i)]!=0)) printf("right key = %d, ",A[right(i)]);
        printf("\n");
    }
    return 0;
}

