从高位往地位贪心即可

# include 
     
      # define IL inline# define RG register# define Fill(a, b) memset(a, b, sizeof(a))using namespace std;typedef long long ll;const int _(1e5 + 10);IL ll Read(){    RG char c = getchar(); RG ll x = 0, z = 1;    for(; c < '0' || c > '9'; c = getchar()) z = c == '-' ? -1 : 1;    for(; c >= '0' && c <= '9'; c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);    return x * z;}int n, m, ans, t[_], op[_];int main(RG int argc, RG char* argv[]){    n = Read(); m = Read();    for(RG int i = 1; i <= n; i++){        RG char c; scanf(" %c", &c); t[i] = Read();        if(c == 'A') op[i] = 1;        else if(c == 'O') op[i] = 2;        else op[i] = 3;    }    for(RG int l = 30; l >= 0; l--){        RG int cnt1 = 1, cnt2 = 0;        for(RG int i = 1; i <= n; i++){            RG int d = (t[i] >> l) & 1;            if(op[i] == 1) cnt1 &= d, cnt2 &= d;            else if(op[i] == 2) cnt1 |= d, cnt2 |= d;            else cnt1 ^= d, cnt2 ^= d;        }        if(cnt2) ans += 1 << l;        else if(cnt1 && m >= (1 << l)) ans += 1 << l, m -= 1 << l;    }    printf("%d\n", ans);    return 0;}