#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define pb push_back
#define mp make_pair
#define all(a) begin(a),end(a)
#define FOR(x,val,to) for(int x=(val);x<int((to));++x)
#define FORE(x,val,to) for(auto x=(val);x<=(to);++x)
#define FORR(x,arr) for(auto &x: arr)
#define FORS(x,plus,arr) for(auto x = begin(arr)+(plus); x != end(arr); ++x)
#define FORREV(x,plus,arr) for(auto x = (arr).rbegin()+(plus); x !=(arr).rend(); ++x)
#define REE(s_) {cout<<s_<<'\n';exit(0);}
#define GET(arr) for(auto &i: (arr)) sc(i)
#define whatis(x) cerr << #x << " is " << (x) << endl;
#define e1 first
#define e2 second
#define INF 0x7f7f7f7f
typedef std::pair<int,int> pi;
typedef std::vector<int> vi;
typedef std::vector<std::string> vs;
typedef int64_t ll;
typedef uint64_t ull;
#define umap unordered_map
#define uset unordered_set
using namespace std;
using namespace __gnu_pbds;

#ifdef _WIN32
#define getchar_unlocked() _getchar_nolock()
#define _CRT_DISABLE_PERFCRIT_LOCKS
#endif
template<class L, class R> ostream& operator<<(ostream &os, map<L, R> P) { for(auto const &vv: P)os<<"("<<vv.first<<","<<vv.second<<")"; return os; }
template<class T> ostream& operator<<(ostream &os, set<T> V) { os<<"[";for(auto const &vv:V)os<<vv<<","; os<<"]"; return os; }
template<class T> ostream& operator<<(ostream &os, vector<T> V) { os<<"[";for(auto const &vv:V)os<<vv<<","; os<<"]"; return os; }
template<class L, class R> ostream& operator<<(ostream &os, pair<L, R> P) { os<<"("<<P.first<<","<<P.second<<")"; return os; }
inline int fstoi(const string &str){auto it=str.begin();bool neg=0;int num=0;if(*it=='-')neg=1;else num=*it-'0';++it;while(it<str.end()) num=num*10+(*it++-'0');if(neg)num*=-1;return num;}
inline void getch(char &x){while(x = getchar_unlocked(), x < 33){;}}
inline void getstr(string &str){str.clear(); char cur;while(cur=getchar_unlocked(),cur<33){;}while(cur>32){str+=cur;cur=getchar_unlocked();}}
template<typename T> inline bool sc(T &num){ bool neg=0; int c; num=0; while(c=getchar_unlocked(),c<33){if(c == EOF) return false;} if(c=='-'){ neg=1; c=getchar_unlocked(); } for(;c>47;c=getchar_unlocked()) num=num*10+c-48; if(neg) num*=-1; return true;}template<typename T, typename ...Args> inline void sc(T &num, Args &...args){ bool neg=0; int c; num=0; while(c=getchar_unlocked(),c<33){;} if(c=='-'){ neg=1; c=getchar_unlocked(); } for(;c>47;c=getchar_unlocked()) num=num*10+c-48; if(neg) num*=-1; sc(args...); }
template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>; //s.find_by_order(), s.order_of_key() <- works like lower_bound
template<typename T> using ordered_map = tree<T, int, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define N 1000001

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    int n;
    string s;
    cin >> n >> s;
    if(s.front() != s.back() || s[0] != 'B') REE(0)
    int m = 2*n;
    int d[m];
    d[0] = 0; //0 -> l;
    int il[2] = {1,0};
    ll res = 1;
    ll mod = 1e9+7;
    FOR(i,1,m){
        d[i] = d[i-1]^(s[i] == s[i-1]);
        ++il[d[i]];
        if(d[i] == 1){
            res *= il[0]--;
            res %= mod;
        }
    }
    if(il[1] != n) REE(0)
    FORE(i,2,n){
        res *= i;
        res %= mod;
    }
    cout << res << '\n';
    /* int a[n*2]; */
    /* iota(a,a+2*n,0); */
    /* int res = 0; */
    /* do{ */
    /*     bool kk = 1; */
    /*     FOR(i,0,n){ */
    /*         if(a[i*2] > a[i*2+1]){ */
    /*             kk = 0; */
    /*             break; */
    /*         } */
    /*     } */
    /*     if(!kk) continue; */
    /*     int xd[n*2+1]; */
    /*     memset(xd,0,sizeof xd); */
    /*     FOR(i,0,n){ */
    /*         ++xd[a[i*2]]; */
    /*         --xd[a[i*2+1]+1]; */
    /*     } */
    /*     FOR(i,1,2*n) */
    /*         xd[i] += xd[i-1]; */
    /*     FOR(i,0,2*n){ */
    /*         xd[i] %= 2; */
    /*         if(xd[i] ^ (s[i] == 'B')){ */
    /*             kk = 0; */
    /*             break; */
    /*         } */
    /*     } */
    /*     if(!kk) continue; */
    /*     ++res; */
    /* }while(next_permutation(a,a+2*n)); */
    /* cout << res << '\n'; */
    /* whatis(res/tgamma(n+1)) */
}



Measured memory_bytes: 1360