# include <bits/stdc++.h> using namespace std; using ll = long long; using ull = unsigned long long; const double pi = acos(-1); template<class T>constexpr T inf() { return ::std::numeric_limits<T>::max(); } template<class T>constexpr T hinf() { return inf<T>() / 2; } template <typename T_char>T_char TL(T_char cX) { return tolower(cX); } template <typename T_char>T_char TU(T_char cX) { return toupper(cX); } template<class T> bool chmin(T& a,T b) { if(a > b){a = b; return true;} return false; } template<class T> bool chmax(T& a,T b) { if(a < b){a = b; return true;} return false; } int popcnt(unsigned long long n) { int cnt = 0; for (int i = 0; i < 64; i++)if ((n >> i) & 1)cnt++; return cnt; } int d_sum(ll n) { int ret = 0; while (n > 0) { ret += n % 10; n /= 10; }return ret; } int d_cnt(ll n) { int ret = 0; while (n > 0) { ret++; n /= 10; }return ret; } ll gcd(ll a, ll b) { if (b == 0)return a; return gcd(b, a%b); }; ll lcm(ll a, ll b) { ll g = gcd(a, b); return a / g*b; }; ll MOD(ll x, ll m){return (x%m+m)%m; } ll FLOOR(ll x, ll m) {ll r = (x%m+m)%m; return (x-r)/m; } template<class T> using dijk = priority_queue<T, vector<T>, greater<T>>; # define all(qpqpq) (qpqpq).begin(),(qpqpq).end() # define UNIQUE(wpwpw) (wpwpw).erase(unique(all((wpwpw))),(wpwpw).end()) # define LOWER(epepe) transform(all((epepe)),(epepe).begin(),TL<char>) # define UPPER(rprpr) transform(all((rprpr)),(rprpr).begin(),TU<char>) # define rep(i,upupu) for(ll i = 0, i##_len = (upupu);(i) < (i##_len);(i)++) # define reps(i,opopo) for(ll i = 1, i##_len = (opopo);(i) <= (i##_len);(i)++) # define len(x) ((ll)(x).size()) # define bit(n) (1LL << (n)) # define pb push_back # define eb emplace_back # define exists(c, e) ((c).find(e) != (c).end()) struct INIT{ INIT(){ std::ios::sync_with_stdio(false); std::cin.tie(0); cout << fixed << setprecision(20); } }INIT; namespace mmrz { void solve(); } int main(){ mmrz::solve(); } #define debug(...) (static_cast<void>(0)) using namespace mmrz; template <std::uint_fast64_t Modulus> class modint { using u64 = std::uint_fast64_t; public: u64 a; constexpr modint(const u64 x = 0) noexcept : a(x % Modulus) {} constexpr u64 &value() noexcept { return a; } constexpr const u64 &value() const noexcept { return a; } constexpr modint operator+(const modint rhs) const noexcept { return modint(*this) += rhs; } constexpr modint operator-(const modint rhs) const noexcept { return modint(*this) -= rhs; } constexpr modint operator*(const modint rhs) const noexcept { return modint(*this) *= rhs; } constexpr modint operator/(const modint rhs) const noexcept { return modint(*this) /= rhs; } constexpr modint &operator+=(const modint rhs) noexcept { a += rhs.a; if (a >= Modulus) { a -= Modulus; } return *this; } constexpr modint &operator-=(const modint rhs) noexcept { if (a < rhs.a) { a += Modulus; } a -= rhs.a; return *this; } constexpr modint &operator*=(const modint rhs) noexcept { a = a * rhs.a % Modulus; return *this; } constexpr modint &operator/=(modint rhs) noexcept { u64 exp = Modulus - 2; while (exp) { if (exp % 2) { *this *= rhs; } rhs *= rhs; exp /= 2; } return *this; } friend std::ostream& operator<<(std::ostream& os, const modint& rhs) { os << rhs.a; return os; } }; using mint = modint<998244353>; template<typename mint> mint power(mint n, long long k) { mint ret = 1; while(k > 0) { if(k & 1)ret *= n; n = n*n; k >>= 1; } return ret; } long long power(long long n, long long k, long long p) { long long ret = 1; while(k > 0){ if(k & 1)ret = ret*n % p; n = n*n % p; k >>= 1; } return ret; } void SOLVE(){ int n, m; cin >> n >> m; string s; cin >> s; vector<vector<int>> g(n); while(m--){ int a, b; cin >> a >> b; a--, b--; g[a].pb(b); g[b].pb(a); } int cq = 0; rep(i, n)if(s[i] == '?')cq++; debug(cq); mint ans = 0; rep(i, n){ if(len(g[i]) < 2)continue; rep(j, len(g[i]))rep(k, len(g[i]))if(j != k){ bool flg = true; int cnt = 0; if(s[g[i][j]] == '?')cnt++; else if(s[g[i][j]] != 'a')flg = false; if(s[i] == '?')cnt++; else if(s[i] != 'o')flg = false; if(s[g[i][k]] == '?')cnt++; else if(s[g[i][k]] != 'i')flg = false; if(not flg)continue; ans += power(26, cq-cnt); } } cout << ans << '\n'; } void mmrz::solve(){ int t = 1; //cin >> t; while(t--)SOLVE(); }