/* 
 * 解説用
 */

#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#include "bits/stdc++.h" // define macro "/D__MAI"

using namespace std;
typedef long long int ll;

#define xprintf(fmt,...) fprintf(stderr,fmt,__VA_ARGS__)
#define debugv(v) {printf("L%d %s > ",__LINE__,#v);for(auto e:v){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) {printf("L%d %s > ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;}
#define debugaa(m,h,w) {printf("L%d %s >\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[y][x]<<" ";}cout<<endl;}}
#define ALL(v) (v).begin(),(v).end()
#define repeat(cnt,l) for(auto cnt=0ll;(cnt)<(l);++(cnt))
#define iterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);++(cnt))
#define MD 1000000007ll
#define PI 3.1415926535897932384626433832795
#define EPS 1e-12
template<typename T1, typename T2> ostream& operator <<(ostream &o, const pair<T1, T2> p) { o << "(" << p.first << ":" << p.second << ")"; return o; }
template<typename iterator> inline size_t argmin(iterator begin, iterator end) { return distance(begin, min_element(begin, end)); }
template<typename iterator> inline size_t argmax(iterator begin, iterator end) { return distance(begin, max_element(begin, end)); }
template<typename T> T& maxset(T& to, const T& val) { return to = max(to, val); }
template<typename T> T& minset(T& to, const T& val) { return to = min(to, val); }
void bye(string s, int code = 0) { cout << s << endl; exit(0); }
mt19937_64 randdev(8901016);
inline ll rand_range(ll l, ll h) {
    return uniform_int_distribution<ll>(l, h)(randdev);
}

#ifdef __MAI
#define getchar_unlocked getchar
#define putchar_unlocked putchar
#endif
#ifdef __VSCC
#define getchar_unlocked _getchar_nolock
#define putchar_unlocked _putchar_nolock
#endif
namespace {
#define isvisiblechar(c) (0x21<=(c)&&(c)<=0x7E)
    class MaiScanner {
    public:
        template<typename T> void input_integer(T& var) {
            var = 0;
            T sign = 1;
            int cc = getchar_unlocked();
            for (; cc<'0' || '9'<cc; cc = getchar_unlocked())
                if (cc == '-') sign = -1;
            for (; '0' <= cc&&cc <= '9'; cc = getchar_unlocked())
                var = (var << 3) + (var << 1) + cc - '0';
            var = var*sign;
        }
        inline int c() { return getchar_unlocked(); }
        inline MaiScanner& operator>>(int& var) {
            input_integer<int>(var);
            return *this;
        }
        inline MaiScanner& operator>>(long long& var) {
            input_integer<long long>(var);
            return *this;
        }
        inline MaiScanner& operator>>(string& var) {
            int cc = getchar_unlocked();
            for (; !isvisiblechar(cc); cc = getchar_unlocked());
            for (; isvisiblechar(cc); cc = getchar_unlocked())
                var.push_back(cc);
            return *this;
        }
        template<typename IT> void in(IT begin, IT end) {
            for (auto it = begin; it != end; ++it) *this >> *it;
        }
    };
}
MaiScanner scanner;

// =============================================================================


// 隣接頂点を保持する有向グラフ
class DGraph {
public:
    size_t n;
    vector<vector<int>> vertex_to;
    vector<vector<int>> vertex_from;

    DGraph(size_t n) :n(n), vertex_to(n), vertex_from(n) {}

    void connect(int from, int to) {
        vertex_to[from].emplace_back(to);
        vertex_from[to].emplace_back(from);
    }
    void resize(size_t _n) {
        n = _n;
        vertex_to.resize(_n);
        vertex_from.resize(_n);
    }
};


// PDCA を 0123 に置き換える
constexpr inline int convert(char c) {
    return
        c == 'P' ? 0 :
        c == 'D' ? 1 :
        c == 'C' ? 2 :
        3;
}


int main() {

    ll n, m;
    // 頂点に書き込まれた文字
    string label;

    scanner >> n >> m;
    scanner >> label;

    // Pと書き込まれた頂点集合，D，C，A
    vector<int> group[4];
    group[0].reserve(n);
    group[1].reserve(n);
    group[2].reserve(n);
    group[3].reserve(n);

    // 各頂点をP,D,C,Aグループに分配
    repeat(i, n) {
        group[convert(label[i])].push_back(i);
    }

    DGraph graph(n);

    repeat(i, m) {
        int u, v;
        scanner >> u >> v;
        --u; --v;
        if (label[u] < label[v])
            swap(u, v);

        int ul = convert(label[u]);
        int vl = convert(label[v]);
        // 題意とは関係の無い辺を除去
        if (ul + 1 != vl)
            continue;

        graph.connect(u, v);
    }

    // DP(あるPに属する頂点から頂点iまで移動する経路は何通りあるか)
    vector<ll> dp(n);

    // P(PからPまで移動する経路は1通り)
    for (int j : group[convert('P')])
        dp[j] = 1;

    // (P->D), (D->C), (C->A)
    repeat(i, 3) {
        for (int i : group[i])
            for (int j : graph.vertex_to[i])
                dp[j] = (dp[j] + dp[i]) % MD;
    }

    ll ans = 0;

    // A(あるPに属する頂点からAまで移動する経路のパターン数の総和が答え)
    for (int j : group[convert('A')])
        ans = (ans + dp[j]) % MD;

    // こたえ
    cout << ans << endl;


    return 0;
}