#include <bits/stdc++.h>

using namespace std;

pair<string, int> a[100005];

int n, m;

int calc(int bit, int now) {

for (int i = 1; i <= n; i++) {

int x = a[i].second >> bit & 1;
	
if (a[i].first == "AND") now &= x;
	
else if (a[i].first == "OR") now |= x;
	
else now ^= x;

}

return now;

}

int main() {

cin >> n >> m;

for (int i = 1; i <= n; i++)

cin >> a[i].first >> a[i].second;

int val = 0, ans = 0;

for (int bit = 29 ; bit >= 0 ; bit--) {

int res0 = calc(bit, 0);
	
int res1 = calc(bit, 1);

if (val + (1 << bit) <= m && res0 < res1)
		
  val += 1 << bit, ans += res1 << bit;
	
else ans += res0 << bit;

}

cout << ans;

return 0;

}