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#include <algorithm>
#include <cstdio>
#include <iostream>
#include <vector>

using namespace std;

const int kMaxN = 1000000;
const int kModulus = 1000 * 1000 * 1000 + 7;

vector<bool> read_buffer(kMaxN);
vector<bool> clause_buffer;

class Clause {
 public:
  Clause() : first(kMaxN), last(0) {}

  static Clause Read() {
    Clause clause;
    char c;
    do {
      if (scanf("%c", &c) == -1) c = '\n';
    } while (c != '(' && c != '\n');
    if (c == '\n') return clause;
    while (c != ')') {
      while (c != '~' && c != 'x') scanf("%c", &c);
      const bool negated = c == '~';
      int i = 0;
      while (c != ' ' && c != ')') {
        scanf("%c", &c);
        if (c >= '0' && c <= '9') {
          // cerr << "Digit " << c << endl;
          i *= 10;
          i += c;
          i -= '0';
          // cerr << i << endl;
        }
      }
      clause.AddLiteral(negated, --i);
    }
    clause.Finalize();
    return clause;
  }

  bool Empty() const { return first > last; }

  void Print() const {
    cerr << first << ' ';
    for (int i = first; i <= last; ++i) cerr << clause_buffer[offset + i - first];
    cerr << endl;
  }

  bool operator<(const Clause& rhs) const { return first == rhs.first ? last > rhs.last : first < rhs.first; }

  int first;
  int last;
  int offset;

 private:
  void AddLiteral(const bool negated, const int i) {
    read_buffer[i] = negated;
    first = min(first, i);
    last = max(last, i);
  }

  void Finalize() {
    offset = clause_buffer.size();
    for (int i = first; i <= last; ++i) clause_buffer.push_back(read_buffer[i]);
  }
};

class Tree {
 public:
  Tree(const int n) : n_(n) {
    levels_.resize(n_ + 2);
    for (int i = 0; i <= n_ + 1; ++i) {
      levels_[i].push_back(value_.size());
      value_.push_back(0);
      left_.push_back(i + 1);
      right_.push_back(i + 1);
    }
    // All-clauses-satisfied state.
    left_[n_] = n_;
    right_[n_] = n_;
    // Some-clause-failed state.
    left_[n_ + 1] = n_ + 1;
    right_[n_ + 1] = n_ + 1;
  }

  void AddClause(const Clause& clause) {
    int state = clause.first;
    int original_state = state;
    for (int i = clause.first; i < clause.last; ++i) {
      // Update tree for non-terminal letter.
      if (clause_buffer[clause.offset + i - clause.first]) {
        left_[state] = left_[original_state];
        original_state = right_[original_state];
        right_[state] = value_.size();
        state = right_[state];
      } else {
        right_[state] = right_[original_state];
        original_state = left_[original_state];
        left_[state] = value_.size();
        state = left_[state];
      }
      levels_[i + 1].push_back(value_.size());
      value_.push_back(0);
      left_.push_back(-1);
      right_.push_back(-1);
    }
    // Update tree for terminal letter.
    if (clause_buffer[clause.offset + clause.last - clause.first]) {
      left_[state] = left_[original_state];
      right_[state] = n_ + 1;
    } else {
      left_[state] = n_ + 1;
      right_[state] = right_[original_state];
    }
  }

  int GetValue() {
    for (int i = 0; i < value_.size(); ++i) value_[i] = 0;
    // Propagate counts.
    value_[0] = 1;
    for (int i = 0; i < n_; ++i) for (int j = 0; j < levels_[i].size(); ++j) {
      const int state = levels_[i][j];
      AddTo(state, left_[state]);
      AddTo(state, right_[state]);
    }
    return value_[n_];
  }

  void Print() {
    for (int i = 0; i < n_; ++i) for (int j = 0; j < levels_[i].size(); ++j) {
      const int state = levels_[i][j];
      cerr << state << " -> " << left_[state] << ' ' << right_[state] << endl;
    }
    cerr << "value: " << GetValue() << endl;
  }

 private:
  void AddTo(const int src, const int dst) {
    value_[dst] += value_[src];
    if (value_[dst] >= kModulus) value_[dst] -= kModulus;
  }

  int n_;
  vector<int> left_;
  vector<int> right_;
  vector<int> value_;
  vector<vector<int> > levels_;
};

bool ReadClause(vector<Clause>* v) {
  const Clause clause = Clause::Read();
  if (clause.Empty()) return false;
  // clause.Print();
  v->push_back(clause);
  return true;
}

int main() {
  int n;
  scanf("%d\n", &n);

  vector<Clause> v;
  while (ReadClause(&v));
  sort(v.rbegin(), v.rend());

  Tree tree(n);
  // tree.Print();
  for (int i = 0; i < v.size(); ++i) {
    // v[i].Print();
    tree.AddClause(v[i]);
    // tree.Print();
  }

  printf("%d\n", tree.GetValue());
  return 0;
}