[NOI2014] 起床困难综合症

#include <bits/stdc++.h>
using namespace std;
const int L = 30;
const int MAXN = 100000;
int n, m;
// 如果第i位是 0/1 最终会变成 0/1
int dig[L + 5][2];
string op[MAXN + 5];
int t[MAXN + 5];
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> n >> m;
    for (int i = 1; i <= n; i++)
        cin >> op[i] >> t[i];
    for (int i = 0; i < L; i++)
    {
        dig[i][0] = 0;
        dig[i][1] = 1;
    }
    /*
    cout << "0:";
    for (int i = 4; i >= 0; i--)
    {
        cout << dig[i][0];
    }
    cout << "\n1:";
    for (int i = 4; i >= 0; i--)
    {
        cout << dig[i][1];
    }
    cout << "\n---\n";
    */
    for (int i = n; i >= 1; i--)
    {
        // cout << op[i] << " " << t[i] << "\n";
        if (op[i] == "AND")
        {
            for (int now = 0; now < L; now++)
            {
                int tDig = ((t[i] >> now) & 1);
                if (tDig == 0)
                {
                    dig[now][0] = dig[now][0];
                    dig[now][1] = dig[now][0];
                }
                else if (tDig == 1)
                {
                    dig[now][0] = dig[now][0];
                    dig[now][1] = dig[now][1];
                }
            }
        }
        else if (op[i] == "OR")
        {
            for (int now = 0; now < L; now++)
            {
                int tDig = ((t[i] >> now) & 1);
                if (tDig == 0)
                {
                    dig[now][0] = dig[now][0];
                    dig[now][1] = dig[now][1];
                }
                else if (tDig == 1)
                {
                    dig[now][0] = dig[now][1];
                    dig[now][1] = dig[now][1];
                }
            }
        }
        else if (op[i] == "XOR")
        {
            for (int now = 0; now < L; now++)
            {
                int tDig = ((t[i] >> now) & 1);
                if (tDig == 0)
                {
                    dig[now][0] = dig[now][0];
                    dig[now][1] = dig[now][1];
                }
                else if (tDig == 1)
                {
                    int pre0 = dig[now][0];
                    dig[now][0] = dig[now][1];
                    dig[now][1] = pre0;
                }
            }
        }
        /*
        cout << "0:";
        for (int i = 4; i >= 0; i--)
        {
            cout << dig[i][0];
        }
        cout << "\n1:";
        for (int i = 4; i >= 0; i--)
        {
            cout << dig[i][1];
        }
        cout << "\n---\n";
        */
    }
    int now = 0;
    int ans = 0;
    for (int i = L - 1; i >= 0; i--)
    {
        if (dig[i][0])
        {
            ans += (1 << i);
        }
        else if (dig[i][1])
        {
            if (now + (1 << i) <= m)
            {
                ans += (1 << i);
                now += (1 << i);
            }
        }
    }
    cout << ans << "\n";
    return 0;
}