#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define db double
#define pii pair<int,int>
#define pli pair<ll,int>
#define pil pair<int,ll>
#define pll pair<ll,ll>
#define ti3 tuple<int,int,int>
#define int128 __int128_t
#define pii128 pair<int128,int128>
const int inf = 1 << 30;
const ll linf = 1e18;
const db EPS = 1e-10;
const db pi = acos(-1);
template<class T> bool chmin(T& x, T y){
    if(x > y) {
        x = y;
        return true;
    } else return false;
}
template<class T> bool chmax(T& x, T y){
    if(x < y) {
        x = y;
        return true;
    } else return false;
}

// overload macro
#define CAT( A, B ) A ## B
#define SELECT( NAME, NUM ) CAT( NAME, NUM )

#define GET_COUNT( _1, _2, _3, _4, _5, _6 /* ad nauseam */, COUNT, ... ) COUNT
#define VA_SIZE( ... ) GET_COUNT( __VA_ARGS__, 6, 5, 4, 3, 2, 1 )

#define VA_SELECT( NAME, ... ) SELECT( NAME, VA_SIZE(__VA_ARGS__) )(__VA_ARGS__)

// rep(overload)
#define rep( ... ) VA_SELECT(rep, __VA_ARGS__)
#define rep2(i, n) for (int i = 0; i < int(n); i++)
#define rep3(i, a, b) for (int i = a; i < int(b); i++)
#define rep4(i, a, b, c) for (int i = a; i < int(b); i += c)

// repll(overload)
#define repll( ... ) VA_SELECT(repll, __VA_ARGS__)
#define repll2(i, n) for (ll i = 0; i < (ll)(n); i++)
#define repll3(i, a, b) for (ll i = a; i < (ll)(b); i++)
#define repll4(i, a, b, c) for (ll i = a; i < (ll)(b); i += c)

// rrep(overload)
#define rrep( ... ) VA_SELECT(rrep, __VA_ARGS__)    
#define rrep2(i, n) for (int i = n - 1; i >= 0; i--)
#define rrep3(i, a, b) for (int i = b - 1; i >= a; i--)
#define rrep4(i, a, b, c) for (int i = b - 1; i >= a; i -= c)

// rrepll(overload)
#define rrepll( ... ) VA_SELECT(rrepll, __VA_ARGS__)
#define rrepll2(i, n) for (ll i = (ll)(n) - 1; i >= 0ll; i--)
#define rrepll3(i, a, b) for (ll i = b - 1; i >= (ll)(a); i--)
#define rrepll4(i, a, b, c) for (ll i = b - 1; i >= (ll)(a); i -= c)

// for_earh
#define fore(e, v) for (auto&& e : v)

// vector
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()

template<class T, T(* op)(T, T), T(* e)()>
struct segment_tree {
private:
    int n, tn;
    vector<T> node;

public:
    segment_tree(int _n, vector<T> a = {}) : tn(_n) {
        n = 1;
        while (n < _n) n *= 2;

        node.resize(2 * n, e());
        if (!a.empty()) {
            for (int i = 0; i < (int)a.size(); i++) {
                update(i, a[i]);
            }
        }
    }

    void update(int i, T val) {
        i += n;
        node[i] = val;
        while (i / 2) {
            i /= 2;
            node[i] = op(node[i * 2], node[i * 2 + 1]);
        }
    }

    T get_val(int l, int r) {
        l += n;
        r += n;
        
        T lval = e(), rval = e();
        while (l < r) {
            if (l & 1) lval = op(lval, node[l++]);
            if (r & 1) rval = op(node[--r], rval);
            l /= 2, r /= 2;
        }

        return op(lval, rval);
    }

    template<class F>
    int right_search(int i, F f) {
        int ret = i, len = 1;
        i += n;
        T val = e();
        while (ret < n) {
            if (i & 1) {
                if (!f(op(val, node[i]))) break;
                val = op(val, node[i]);
                ret += len;
                i++;
            }
            len *= 2, i /= 2;
        }

        if (ret == n) return tn;

        while (len > 1) {
            len /= 2, i *= 2;
            if (f(op(val, node[i]))) {
                val = op(val, node[i]);
                ret += len;
                i++;
            }
        }

        return min(ret, tn);
    }

    template<class F>
    int left_search(int i, F f) {
        int ret = i, len = 1;
        i += n;
        T val = e();
        while (ret > 0) {
            if (i & 1) {
                i--;
                if (!f(op(node[i], val))) break;
                val = op(node[i], val);
                ret -= len;
            }
            len *= 2, i /= 2;
        }

        if (ret == 0) return 0;

        while (len > 1) {
            len /= 2, i = i * 2 + 1;
            if (f(op(node[i], val))) {
                val = op(node[i], val);
                ret -= len;
                i--;
            }
        }

        return ret;
    }
};

// 表

int idx[26];
int nxt[26];

struct node {
    int dp[6][8];
    node() {
        rep (i, 6) rep (j, 8) dp[i][j] = -inf;
    }
};

node op(node a, node b) {
    node ret;
    rep (i, 6) rep (j, 8) {
        chmax(ret.dp[i][j], max(a.dp[i][j], b.dp[i][j]));
    }
    // くっつける
    rep (i, 6) rep (j, 7) rep (k, 8) {
        if (a.dp[i][j] == -inf || b.dp[nxt[j]][k] == -inf) continue;
        chmax(ret.dp[i][k], a.dp[i][j] + b.dp[nxt[j]][k] + 2);
    }

    vector<int> mxa(6, -inf), mxb(8, -inf);
    rep (i, 6) rep (j, 8) {
        chmax(mxa[i], a.dp[i][j]);
        chmax(mxb[j], b.dp[i][j]);
    }
    rep (i, 6) rep (j, 8) {
        chmax(ret.dp[i][j], mxa[i] + mxb[j]);
    }
    return ret;
}

node e() {
    return node();
}

int n, q;
string s;
int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(20);
    cin >> n >> q >> s;
    segment_tree<node, op, e> st(n);

    string con = "drmfslt";
    string to = "oeiaoai";
    string vow = "aiueo";
    set<int> cons, vows;
    rep (i, vow.size()) {
        vows.insert(vow[i] - 'a');
        idx[vow[i] - 'a'] = i;
    }
    rep (i, con.size()) {
        cons.insert(con[i] - 'a');
        idx[con[i] - 'a'] = i;
        nxt[i] = idx[to[i] - 'a'];
    }

    rep (i, n) {
        int ci = s[i] - 'a';
        node nd;
        if (cons.find(ci) != cons.end()) {
            nd.dp[5][idx[ci]] = 0;
        }
        if (vows.find(ci) != vows.end()) {
            nd.dp[idx[ci]][7] = 0;
        }
        st.update(i, nd);
    }

    rep (_, q) {
        char c;
        int l, r;
        cin >> c >> l >> r;
        l--;
        if (c == '?') {
            node val = st.get_val(l, r);
            int mx = 0;
            rep (i, 6) rep (j, 8) chmax(mx, val.dp[i][j]);
            cout << r - l - mx << '\n';
        } else {
            string t;
            cin >> t;
            rep (i, t.size()) {
                int ci = t[i] - 'a';
                node nd;
                if (cons.find(ci) != cons.end()) {
                    nd.dp[5][idx[ci]] = 0;
                }
                if (vows.find(ci) != vows.end()) {
                    nd.dp[idx[ci]][7] = 0;
                }
                st.update(l + i, nd);
            }
        }
    }
}