/* Kristoffer Hansen. arnsfelt@daimi.au.dk */

#include <stdio.h>
#include <stdlib.h>

#define MAXN 21

int N,n,k;
int mask;
char done[MAXN+1];
int *O[MAXN+1];
char placed[1<<MAXN];

int bits[1<<MAXN];
char stat[1<<MAXN];

void placeit()
{
  int i;
  int next;

  placed[0]=1;
  i=0;
  bits[0]=0;
  stat[0]=0;

  for (;;) {    
    O[n][i]=bits[i];
    next=(bits[i]<<1)&mask;
    if (i==(1<<n)-n-1 && !placed[next+1]) {
      i++;
      next++;
      while (i<(1<<n)) {
	O[n][i]=next;
	next=(next<<1)&mask;
	i++;
      }
      return;
    }
    switch (stat[i]) {
    case 0:
      stat[i]=2;
      if (!placed[next]) {
	stat[i]=1;
	placed[next]=1;
	bits[i+1]=next;
	stat[i+1]=0;
	i++;
      }
      break;
    case 1:
      placed[next]=0;
    case 2:
      next++;
      stat[i]=4;
      if (!placed[next] && i<(1<<n)-n) {
	stat[i]=3;
	placed[next]=1;
	bits[i+1]=next;
	stat[i+1]=0;
	i++;
      }
      break;
    case 3:
      next++;
      placed[next]=0;
    case 4:
      i--;
    }
  }
}


int main()
{
  int i;

  scanf("%d",&N);
  for (i=1; i<=MAXN; i++) {
    done[i]=0;
    O[i] = (int*)malloc((1<<i) * sizeof(int));
  }
  while (N-->0) {
    scanf("%d %d",&n,&k);
    if (!done[n]) {
      done[n]=1;
      mask = (1<<n)-1;
      for (i=0; i<=mask; i++)
	placed[i]=0;
      placeit();
    }
    printf("%d\n",O[n][k]);
  }
  return 0;
}