#include <stdio.h>
#define MAX 100000
int main(void){
    int n,i,A[MAX + 1];
    scanf("%d",&n);
    for(i=1;i<=n;i++) scanf("%d",&A[i]);
    
    for(i=1;i<=n;i++){
        printf("node %d: key = %d, ",i,A[i]);
        if((i/2) >= 1) printf("parent key = %d, ",A[i/2]);
        if((2*i) <= n) printf("left key = %d, ",A[2*i]);
        if((2*i+1) <= n) printf("right key = %d, ",A[2*i+1]);
        printf("\n");
    }
    return 0;
}

