//#define _GLIBCXX_DEBUG #include <bits/stdc++.h> using namespace std; #define rep(i, n) for (int i = 0; i < (ll)(n); i++) #define all(a) (a).begin(), (a).end() using ll = long long; const int INF32 = 2e9; const ll INF64 = 4e18; const ll MOD = 998244353; vector<ll> P26={1}; ll power26(int x){ while(P26.size()<=x){ P26.push_back(P26[P26.size()-1]*26%MOD); } return P26[x]; } int main() { int N, M; string S; cin >> N >> M >> S; vector<vector<int>> G(N,vector<int>(0)); int questioncnt = 0; rep(i,N){ if(S[i]=='?')questioncnt++; } rep(i,M){ int Ai, Bi; cin >> Ai >> Bi; Ai--;Bi--; G[Ai].push_back(Bi); G[Bi].push_back(Ai); } ll ans = 0; rep(i,N){ if (!(S[i]=='?'||S[i]=='o'))continue; int x26_1 = questioncnt; if(S[i]=='?')x26_1--; for(int j = 0; j < G[i].size(); j++){ for(int k = j+1; k < G[i].size(); k++){ int x26_2 = x26_1; if(!(S[G[i][j]]=='a'||S[G[i][j]]=='i'||S[G[i][j]]=='?'))continue; if(!(S[G[i][k]]=='a'||S[G[i][k]]=='i'||S[G[i][j]]=='?'))continue; if((S[G[i][j]]=='a'||S[G[i][j]]=='i')&&S[G[i][j]]==S[G[i][k]])continue; if(S[G[i][j]]=='?')x26_2--; if(S[G[i][k]]=='?')x26_2--; if(S[G[i][k]]=='?'&&S[G[i][j]]=='?'){ ans += 2*power26(x26_2); ans %= MOD; } else { ans += power26(x26_2); ans %= MOD; } } } } cout << ans << endl; return 0; }