#include <bits/stdc++.h>
using namespace std;

using ll = long long;

const int MOD = 998244353;

ll modpow(ll a, ll n) {
    ll r = 1;
    while (n) {
        if (n & 1) r = r * a % MOD;
        a = a * a % MOD;
        n >>= 1;
    }
    return r;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, Q;
    cin >> N >> Q;

    string S;
    cin >> S;

    vector<ll> fact(N + 1), invfact(N + 1);

    fact[0] = 1;
    for (int i = 1; i <= N; ++i) {
        fact[i] = fact[i - 1] * i % MOD;
    }

    invfact[N] = modpow(fact[N], MOD - 2);
    for (int i = N; i >= 1; --i) {
        invfact[i - 1] = invfact[i] * i % MOD;
    }

    auto C = [&](int n, int k) -> ll {
        if (k < 0 || k > n) return 0;
        return fact[n] * invfact[k] % MOD * invfact[n - k] % MOD;
    };

    auto cat = [&](int r) -> ll {
        return fact[2 * r] * invfact[r] % MOD * invfact[r + 1] % MOD;
    };

    auto solve = [&](int K) -> ll {
        ll P = 1;
        int last = 0;
        int B = 0;

        for (int i = 1; i < N; ++i) {
            if (S[i - 1] == S[i]) continue;

            if (i & 1) {
                return 0;
            }

            P = P * cat((i - last) / 2) % MOD;
            last = i;
            B = i;
        }

        int L = N - B;
        int q = K - B / 2;

        if (S[N - 1] == 'Y') {
            if (!(0 <= q && q <= L / 2)) return 0;

            ll f = (C(L, q) - C(L, q - 1) + MOD) % MOD;
            return P * f % MOD;
        } else {
            if (!((L + 1) / 2 <= q && q <= L)) return 0;

            ll f = (C(L, q) - C(L, q + 1) + MOD) % MOD;
            return P * f % MOD;
        }
    };

    while (Q--) {
        int t, x;
        cin >> t >> x;

        if (t == 1) {
            --x;
            S[x] = (S[x] == 'Y' ? 'N' : 'Y');
        } else {
            cout << solve(x) << '\n';
        }
    }
}