#include using namespace std; typedef long long ll; typedef pair P; #define DUMP(x) cout << #x << " = " << (x) << endl; #define FOR(i, m, n) for (ll i = m; i < n; i++) #define IFOR(i, m, n) for (ll i = n - 1; i >= m; i--) #define REP(i, n) FOR(i, 0, n) #define IREP(i, n) IFOR(i, 0, n) #define ALL(v) (v).begin(), (v).end() #define SZ(x) ll(x.size()) // modint template struct Fp { long long val; constexpr Fp(long long v = 0) noexcept : val(v % MOD) { if (val < 0) val += MOD; } constexpr int getmod() { return MOD; } constexpr Fp operator-() const noexcept { return val ? MOD - val : 0; } constexpr Fp operator+(const Fp& r) const noexcept { return Fp(*this) += r; } constexpr Fp operator-(const Fp& r) const noexcept { return Fp(*this) -= r; } constexpr Fp operator*(const Fp& r) const noexcept { return Fp(*this) *= r; } constexpr Fp operator/(const Fp& r) const noexcept { return Fp(*this) /= r; } constexpr Fp& operator+=(const Fp& r) noexcept { val += r.val; if (val >= MOD) val -= MOD; return *this; } constexpr Fp& operator-=(const Fp& r) noexcept { val -= r.val; if (val < 0) val += MOD; return *this; } constexpr Fp& operator*=(const Fp& r) noexcept { val = val * r.val % MOD; return *this; } constexpr Fp& operator/=(const Fp& r) noexcept { long long a = r.val, b = MOD, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } val = val * u % MOD; if (val < 0) val += MOD; return *this; } constexpr bool operator==(const Fp& r) const noexcept { return this->val == r.val; } constexpr bool operator!=(const Fp& r) const noexcept { return this->val != r.val; } friend constexpr ostream& operator<<(ostream& os, const Fp& x) noexcept { return os << x.val; } friend constexpr Fp modpow(const Fp& a, long long n) noexcept { if (n == 0) return 1; auto t = modpow(a, n / 2); t = t * t; if (n & 1) t = t * a; return t; } }; // binomial coefficient template struct BiCoef { vector fact_, inv_, finv_; constexpr BiCoef() {} constexpr BiCoef(int n) noexcept : fact_(n, 1), inv_(n, 1), finv_(n, 1) { init(n); } constexpr void init(int n) noexcept { fact_.assign(n, 1), inv_.assign(n, 1), finv_.assign(n, 1); int MOD = fact_[0].getmod(); for (int i = 2; i < n; i++) { fact_[i] = fact_[i - 1] * i; inv_[i] = -inv_[MOD % i] * (MOD / i); finv_[i] = finv_[i - 1] * inv_[i]; } } constexpr T com(int n, int k) const noexcept { if (n < k || n < 0 || k < 0) return 0; if (n <= (int)fact_.size() - 1) { return fact_[n] * finv_[k] * finv_[n - k]; } // C(n,k), n <= 1e9, k <= 1e6 T res = 1; for (int i = n; i >= n - k + 1; i--) { T a = i; res *= a; } res *= finv_[k]; return res; } constexpr T fact(int n) const noexcept { if (n < 0) return 0; return fact_[n]; } constexpr T inv(int n) const noexcept { if (n < 0) return 0; return inv_[n]; } constexpr T finv(int n) const noexcept { if (n < 0) return 0; return finv_[n]; } }; const int MOD = 1000000007; // const int MOD = 998244353; using mint = Fp; BiCoef bc; ll n; string s; string t = "yukicoder"; // sのi文字目,tのj文字目, ?の個数 mint dp[100005][10][2]; int main() { cin >> n >> s; dp[0][0][0] = 1; REP(i, n) { ll idx = -1; REP(l, SZ(t)) { if (t[l] == s[i]) { idx = l; break; } } if (s[i] != '?' && idx != -1) { REP(k, 2) { dp[i + 1][idx + 1][k] += dp[i][idx][k]; } } REP(j, SZ(t) + 1) { REP(k, 2) { mint v = dp[i][j][k]; dp[i + 1][j][k] += v; if (s[i] == '?' && j + 1 <= SZ(t) && k + 1 <= 1) { dp[i + 1][j + 1][k + 1] += v; } } } } mint ans = 0; REP(k, 2) { ans += dp[n][SZ(t)][k]; } cout << ans << endl; }