#include <bits/stdc++.h>

 #define miaom(x,y) ((x & (1<<y))>>y)

 using namespace std;

 int n,m,p[],a[],in[];

 char opt[];

 char getch()

 {

     char ch;

     for(ch=getchar();!isalpha(ch);ch=getchar());

     return ch;

 }

 int main()

 {

     scanf("%d%d",&n,&m);

     for(int i=;i<=n;i++)

     {

         opt[i]=getch();

         getch();if(opt[i]!='O')getch();

         scanf("%d",&p[i]);

     }

     int ans=;

     for(int i=;i>=;i--)

     {

         bool a=,b=;

         for(int j=;j<=n;j++)

         if(opt[j]=='A')

             a&=miaom(p[j],i),

             b&=miaom(p[j],i);

         else

         if(opt[j]=='O')

             a|=miaom(p[j],i),

             b|=miaom(p[j],i);

         else

         if(opt[j]=='X')

             a^=miaom(p[j],i),

             b^=miaom(p[j],i);

         if(a) ans+=<<i;

         else

         if(b && m>=<<i) m-=<<i,ans+=<<i;

     }

     printf("%d\n",ans);

     return ;

 }