// includes {{{
#include<iostream>
#include<iomanip>
#include<algorithm>
#include<vector>
#include<stack>
#include<queue>
#include<map>
#include<set>
#include<tuple>
#include<cmath>
#include<random>
#include<cassert>
// #include<deque>
// #include<multiset>
// #include<bitset>
// #include<cstring>
// #include<bits/stdc++.h>
// }}}
using namespace std;
using ll = long long;

// #undef DEBUG
// #define DEBUG
// DEBUG {{{
#include <array>
#include <deque>
#include <iostream>
#include <list>
#include <queue>
#include <stack>
#include <tuple>
#include <valarray>
#include <vector>
// clang-format off
template<int n, class...T> typename enable_if<(n>=sizeof...(T))>::type _ot(ostream &, tuple<T...> const &){}
template<int n, class...T> typename enable_if<(n< sizeof...(T))>::type _ot(ostream & os, tuple<T...> const & t){ os << (n==0?"":", ") << get<n>(t); _ot<n+1>(os, t); }
template<class...T> ostream & operator<<(ostream &o, tuple<T...> const &t){ o << "("; _ot<0>(o, t); o << ")"; return o; }
template<class T, class U> ostream & operator<<(ostream &o, pair<T, U> const &p) { o << "(" << p.first << ", " << p.second << ")"; return o; }
template < class T > ostream &operator<<(ostream &o, const stack<T> &a) { o << "{"; for(auto tmp = a; tmp.size(); tmp.pop()) o << (a.size() == tmp.size() ? "" : ", ") << tmp.top(); o << "}"; return o; }
template <class T, class Container, class Compare > ostream &operator<<(ostream &os, priority_queue<T, Container, Compare> a) { os << "{ (top) "; while(a.size()) os << a.top() << (a.size() == 1 ? "" : ", "), a.pop(); os << " }"; return os; }
template <class T, class Container > ostream &operator<<(ostream &os, queue<T, Container> a) { os << "{ "; while(a.size()) os << a.front() << (a.size() == 1 ? "" : ", "), a.pop(); os << " }"; return os; }
#ifdef DEBUG
#if !defined(DEBUG_OUT)
#define DEBUG_OUT cerr
#endif
#if !defined(DEBUG_LEFT)
#define DEBUG_LEFT "\e[1;36m"
#endif
#if !defined(DEBUG_RIGHT)
#define DEBUG_RIGHT ":\e[m"
#endif
#define dump(...) [&](){auto __debug_tap=make_tuple(__VA_ARGS__);DEBUG_OUT<<DEBUG_LEFT<<__LINE__ << DEBUG_RIGHT << " " <<#__VA_ARGS__<<" = "<<__debug_tap<<endl;}()
template < class T > inline void dump2D(T &d, size_t sizey, size_t sizex) { for(size_t i = 0; i < sizey; i++) { DEBUG_OUT << "\t"; for(size_t j = 0; j < sizex; j++) DEBUG_OUT << d[i][j] << (j + 1 == sizex ? "" : "\t"); DEBUG_OUT << endl; } }
template < class T, class = typename iterator_traits< decltype(begin(T())) >::value_type, class = typename enable_if<!is_same<T, string>::value>::type > ostream &operator<<(ostream &o, const T &a) { o << "{"; for(auto ite = begin(a); ite != end(a); ++ite) o << (ite == begin(a) ? "" : ", ") << *ite; o << "}"; return o; }
#else
#define dump(...) (42)
#define dump2D(...) (42)
template < class T, class = typename iterator_traits< decltype(begin(T())) >::value_type, class = typename enable_if<!is_same<T, string>::value>::type > ostream &operator<<(ostream &o, const T &a) { for(auto ite = begin(a); ite != end(a); ++ite) o << (ite == begin(a) ? "" : " ") << *ite; return o; }
#endif
// clang-format on
// }}}


/// --- ModInt Library {{{ ///
#include <ostream>
template < ll mod = (ll) 1e9 + 7 >
struct ModInt {
  // math {{{
  static inline ll extgcd(ll a, ll b, ll &x, ll &y) {
    ll d;
    return b == 0 ? (x = 1, y = 0, a) : (d = extgcd(b, a % b, y, x), y -= a / b * x, d);
  }
  static inline ll modinv(ll a) {
    ll x = 0, y = 0;
    extgcd(a, mod, x, y);
    if(x < 0) x += mod;
    return x;
  }
  static inline ll modpow(ll a, ll b) {
    if(b < 0) b = -b, a = modinv(a);
    ll r = 1;
    a %= mod;
    while(b) {
      if(b & 1) r = r * a % mod;
      a = a * a % mod;
      b >>= 1;
    }
    return r;
  }
  // }}}

  ll val;
  constexpr ModInt() : val(0) {}
  constexpr ModInt(ll t) {
    val = t % mod;
    if(val < 0) val += mod;
  }

private:
  // strict constructor
  constexpr ModInt(ll t, int) : val(t) {}

public:
  template < class T >
    explicit operator T() {
      return T(val);
    }
  // ModInt <arithmetic-operator>[=] ModInt {{{
  ModInt operator+(ModInt const &rhs) const {
    ModInt tmp = *this;
    tmp += rhs;
    return tmp;
  }
  ModInt operator-(ModInt const &rhs) const {
    ModInt tmp = *this;
    tmp -= rhs;
    return tmp;
  }
  ModInt operator*(ModInt const &rhs) const {
    ModInt tmp = *this;
    tmp *= rhs;
    return tmp;
  }
  ModInt operator/(ModInt const &rhs) const {
    ModInt tmp = *this;
    tmp /= rhs;
    return tmp;
  }
  ModInt &operator+=(ModInt const &rhs) {
    val = val + rhs.val;
    if(val >= mod) val -= mod;
    return *this;
  }
  ModInt &operator-=(ModInt const &rhs) { return *this += -rhs; }
  ModInt &operator*=(ModInt const &rhs) {
    val = val * rhs.val % mod;
    return *this;
  }
  ModInt &operator/=(ModInt const &rhs) { return *this *= rhs.inv(); }
  // }}}
  // increment, decrement {{{
  ModInt operator++(int) {
    ModInt tmp = *this;
    val = val + 1;
    if(val >= mod) val = 0;
    return tmp;
  }
  ModInt operator--(int) {
    ModInt tmp = *this;
    val = val == 0 ? mod - 1 : val - 1;
    return tmp;
  }
  ModInt &operator++() {
    val = val + 1;
    if(val >= mod) val = 0;
    return *this;
  }
  ModInt &operator--() {
    val = val == 0 ? mod - 1 : val - 1;
    return *this;
  }
  // }}}
  ModInt operator-() const { return ModInt(val == 0 ? 0 : mod - val, 0); }
  // ModInt <arithmetic-operator>[=] T {{{
  template < typename T >
    ModInt operator+(T const &rhs) const {
      return ModInt(val + rhs % mod);
    }
  template < typename T >
    ModInt operator-(T const &rhs) const {
      return ModInt(mod + val - rhs % mod);
    }
  template < typename T >
    ModInt operator*(T const &rhs) const {
      return ModInt(val * (rhs % mod));
    }
  template < typename T >
    ModInt operator/(T const &rhs) const {
      return ModInt(val * modinv(rhs));
    }
  template < typename T >
    ModInt &operator+=(T const &rhs) {
      val = (mod + val + rhs % mod) % mod;
      return *this;
    }
  template < typename T >
    ModInt &operator-=(T const &rhs) {
      val = (mod + val - rhs % mod) % mod;
      return *this;
    }
  template < typename T >
    ModInt &operator*=(T const &rhs) {
      val = val * (mod + rhs % mod) % mod;
      return *this;
    }
  template < typename T >
    ModInt &operator/=(T const &rhs) {
      val = val * modinv(rhs, mod) % mod;
      return *this;
    }
  // }}}
  ModInt inv() const { return ModInt(modinv(val), 0); }
  ModInt operator~() const { return inv(); }
  friend ostream &operator<<(ostream &os, ModInt const &mv) {
    os << mv.val;
    return os;
  }
  // T <arithmetic-operator> ModInt {{{
  friend constexpr ModInt operator+(ll a, ModInt const &mv) {
    return ModInt(a % mod + mv.val);
  }
  friend constexpr ModInt operator-(ll a, ModInt const &mv) {
    return ModInt(a % mod - mv.val);
  }
  friend constexpr ModInt operator*(ll a, ModInt const &mv) {
    return ModInt((mod + a % mod) * mv.val % mod, 0);
  }
  friend constexpr ModInt operator/(ll a, ModInt const &mv) {
    return ModInt((mod + a % mod) * modinv(mv.val) % mod, 0);
  }
  // }}}
  // power {{{
  ModInt operator^(ll x) const { return pow(*this, x); }
  ModInt &operator^=(ll x) {
    val = modpow(val, x);
    return *this;
  }
  friend ModInt pow(ModInt x, ll y) { return ModInt(modpow(x.val, y), 0); }
  // }}}
};
/// }}}--- ///

using mint = ModInt<>;

mint dp[201][201]; // [i][j] := i個決めた時，古い順はj個下に繋げられるようになっているときの場合の数

int main() {
  ios::sync_with_stdio(false), cin.tie(0);
  int n = 0, m; cin >> m;
  vector<int> up;
  for(int i = 0; i < m; i++) {
    char c;
    cin >> c;
    if(c == 'D') n++, up.emplace_back(1); // 上へと結ぶ，という意味で入れ替わっている
    if(c == 'U') n++, up.emplace_back(0);
  }

  dp[0][0] = 1;
  for(int i = 0; i < n; i++) {
    for(int j = 0; j <= i; j++) {
      // jだけ，新しい順位を下につなげられる
      if(up[i]) {
        // これ自体はj個から選ぶ
        if(j >= 1) {
          // 古い順の (i+1) を
          // 下に向けるとき
          dp[i+1][j] += dp[i][j] * j;
          // 上に向けるとき
          dp[i+1][j-1] += dp[i][j] * j * j;
        }
      } else {
        // 下に向けるとき
        dp[i+1][j+1] += dp[i][j];
        // 上に向けるとき
        if(j >= 1) dp[i+1][j] += dp[i][j] * j;
      }
    }
  }

  cout << dp[n][0] << endl;
  return 0;
}



Measured memory_bytes: 3488