#include<stdio.h>
#define N 200000
int main(){
  int n, i;
   int A[N+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 ( i*2 <= n ) printf(" left key = %d,", A[i*2]);
     if ( i*2+1 <= n ) printf(" right key = %d,", A[i*2+1]);
     printf("\n");
   }
  return 0;
}

