#include <bits/stdc++.h>

using namespace std;

int n, m, t, a, r, z, o = 0x3fffffff;
string op;

int main()
{
    cin >> n >> m;
    while (n--)
    {
        cin >> op >> t;
        if (op[0] ^ 65)
            if (op[0] ^ 88) z |= t, o |= t;
            else z ^= t, o ^= t;
        else z &= t, o &= t;
    }
    
    for (int i = 29; ~i; i--)
        if (a | 1 << i <= m && o >> i & 1 > z >> i & 1) a |= 1 << i, r |= 1 << i;
        else r |= z & 1 << i;

    cout << r;

    return 0;
}