#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using Vi = vector<int>;
using Pii = pair<int,int>;
#define mp make_pair
#define pb push_back
#define x first
#define y second
#define rep(i,b,e) for(int i = (b); i < (e); i++)
#define each(a, x) for(auto& a : (x))
#define all(x) (x).begin(),(x).end()
#define sz(x) int((x).size())

#define tem template<class t,class u,class...w>
#define pri(x,y)tem auto operator<<(t& o, u a)->decltype(x,o) { o << y; return o; }
pri(a.print(), "{"; a.print(); "}");
pri(a.y, "(" << a.x << ", " << a.y << ")");
pri(all(a), "["; auto d=""; for (auto i : a) (o << d << i, d = ", "); o << "]");
void DD(...) {}
tem void DD(t s, u a, w... k) {
	for (int b = 44; *s && *s - b; cerr << *s++)
		b += ((*s == 41) - (*s == 40)) * 88;
	cerr << ": " << a << *s++; DD(s, k...);
}
tem vector<t> span(const t* a, u n) { return {a, a+n}; }
#ifdef LOC
#define deb(...) (DD("[,\b :] "#__VA_ARGS__, __LINE__, __VA_ARGS__), cerr << endl)
#else
#define deb(...)
#endif
#define DBP(...) void print() { DD(#__VA_ARGS__, __VA_ARGS__); }

constexpr char AMIN = 'a';
constexpr int ALPHA = 26;

struct Aho {
	vector<array<int, ALPHA>> nxt{1};
	Vi suf = {-1}, accLink = {-1};
	vector<Vi> accept{1};

	bool isAcc(int i) {
		return !accept[i].empty() || accLink[i] > 0;
	}

	int add(const string& str, int id) {
		int i = 0;
		each(c, str) {
			if (!nxt[i][c-AMIN]) {
				nxt[i][c-AMIN] = sz(nxt);
				nxt.pb({}); suf.pb(-1);
				accLink.pb(1); accept.pb({});
			}
			i = nxt[i][c-AMIN];
		}
		accept[i].pb(id);
		return i;
	}

	void build() {
		queue<int> que;

		each(e, nxt[0]) if (e) {
			suf[e] = 0; que.push(e);
		}

		while (!que.empty()) {
			int i = que.front(), s = suf[i], j = 0;
			que.pop();
			each(e, nxt[i]) {
				if (e) que.push(e);
				(e ? suf[e] : e) = nxt[s][j++];
			}
			accLink[i] = (accept[s].empty() ? accLink[s] : s);
		}
	}
};

constexpr ll MOD = 1e9+7;
using Mat = vector<vector<ll>>;

Mat mul(const Mat& a, const Mat& b) {
	int n = sz(a);
	Mat c(n, vector<ll>(n));

	rep(i, 0, n) {
		rep(j, 0, n) {
			ll tmp = 0;
			rep(k, 0, n) {
				tmp += a[i][k] * b[k][j] % MOD;
			}
			c[i][j] = tmp % MOD;
		}
	}

	return c;
}

Mat matPow(Mat a, ll e) {
	Mat t(sz(a), vector<ll>(sz(a)));
	rep(i, 0, sz(a)) t[i][i] = 1;
	while (e) {
		if (e % 2) t = mul(t, a);
		e /= 2; a = mul(a, a);
	}
	return t;
}

int main() {
	cin.sync_with_stdio(0); cin.tie(0);
	cout << fixed << setprecision(12);

	int n, q; cin >> n >> q;

	Aho aho;

	rep(i, 0, q) {
		int l; cin >> l;
		string s; cin >> s;
		aho.add(s, i+1);
	}

	aho.build();

	int dim = sz(aho.nxt);
	Mat mat(dim, vector<ll>(dim));

	rep(i, 0, dim) {
		if (aho.isAcc(i)) continue;
		rep(a, 0, ALPHA) {
			int j = aho.nxt[i][a];
			if (aho.isAcc(j)) continue;
			mat[i][j]++;
		}
	}

	deb(mat, dim);

	Mat res = matPow(mat, n);
	ll ans = 0;

	deb(res);

	rep(i, 0, dim) {
		ans += res[0][i];
		ans %= MOD;
	}

	ans %= MOD;
	if (ans < 0) ans += MOD;
	cout << ans << endl;
	return 0;
}