#include <bits/stdc++.h>
using ll = long long;
using std::cin;
using std::cout;
using std::endl;
std::mt19937 rnd(std::chrono::steady_clock::now().time_since_epoch().count());
template <class T>
inline bool chmax(T &a, T b)
{
  if (a < b)
  {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmin(T &a, T b)
{
  if (a > b)
  {
    a = b;
    return 1;
  }
  return 0;
}

const int inf = (int)1e9 + 7;
const long long INF = 1LL << 60;

template <int mod>
struct ModInt
{
  int x;

  ModInt() : x(0) {}

  ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}

  ModInt &operator+=(const ModInt &p)
  {
    if ((x += p.x) >= mod)
      x -= mod;
    return *this;
  }

  ModInt &operator-=(const ModInt &p)
  {
    if ((x += mod - p.x) >= mod)
      x -= mod;
    return *this;
  }

  ModInt &operator*=(const ModInt &p)
  {
    x = (int)(1LL * x * p.x % mod);
    return *this;
  }

  ModInt &operator/=(const ModInt &p)
  {
    *this *= p.inverse();
    return *this;
  }

  ModInt operator-() const { return ModInt(-x); }

  ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }

  ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }

  ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }

  ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }

  bool operator==(const ModInt &p) const { return x == p.x; }

  bool operator!=(const ModInt &p) const { return x != p.x; }

  ModInt inverse() const
  {
    int a = x, b = mod, u = 1, v = 0, t;
    while (b > 0)
    {
      t = a / b;
      std::swap(a -= t * b, b);
      std::swap(u -= t * v, v);
    }
    return ModInt(u);
  }

  ModInt pow(int64_t n) const
  {
    ModInt ret(1), mul(x);
    while (n > 0)
    {
      if (n & 1)
        ret *= mul;
      mul *= mul;
      n >>= 1;
    }
    return ret;
  }

  friend std::ostream &operator<<(std::ostream &os, const ModInt &p)
  {
    return os << p.x;
  }

  friend std::istream &operator>>(std::istream &is, ModInt &a)
  {
    int64_t t;
    is >> t;
    a = ModInt<mod>(t);
    return (is);
  }

  static int get_mod() { return mod; }
};

constexpr int mod = (int)1e9 + 7;
using mint = ModInt<mod>;
void solve([[maybe_unused]] int CASE)
{
  int n;
  std::string s;
  cin >> n >> s;
  const std::string t = "yukicoder";
  std::vector dp(2, std::vector(2, std::vector<mint>(t.size() + 1)));
  int cur = 0, nxt = 1;
  dp[0][0][0] = 1;
  for (int i = 0; i < n; ++i)
  {
    for (int j = 0; j < 2; ++j)
    {
      for (int k = 0; k <= (int)t.size(); ++k)
      {
        dp[nxt][j][k] = 0;
      }
    }
    for (int j = 0; j < 2; ++j)
    {
      for (int k = 0; k <= (int)t.size(); ++k)
      {
        dp[nxt][j][k] += dp[cur][j][k];
        if (k + 1 <= (int)t.size())
        {
          if (s[i] == '?' and j == 0)
          {
            dp[nxt][1][k + 1] += dp[cur][j][k];
          }
          if (s[i] == t[k])
          {
            dp[nxt][j][k + 1] += dp[cur][j][k];
          }
        }
      }
    }
    std::swap(cur, nxt);
  }
  mint res = 0;
  for (int i = 0; i < 2; ++i)
  {
    res += dp[cur][i][(int)t.size()];
  }
  cout << res << "\n";
}

int main()
{
  std::cin.tie(nullptr);
  std::ios::sync_with_stdio(false);

  int kkt = 1;
  // cin >> kkt;
  for (int jupi = 1; jupi <= kkt; jupi++)
    solve(jupi);
  return 0;
}